5-halouracil-modified micrornas and their use in the treatment of cancer

ABSTRACT

The present disclosure provides nucleic acid compositions that incorporate one or more halouracil molecules. More specifically, the present disclosure reveals that the replacement of uracil nucleotides within a microRNA nucleotide sequence with a 5-halouracil increases the ability of the micro-RNA to inhibit cancer progression and tumorigenesis. As such, the present disclosure provides various nucleic acid (e.g., microRNA) compositions having 5-halouracil molecules incorporated in their nucleic acid sequences and methods for using the same. The present disclosure further provides pharmaceutical compositions comprising the modified nucleic acid compositions, and methods for treating cancers using the same.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of co-pending application having U.S.Ser. No. 16/912,932, filed Jun. 26, 2020, which is acontinuation-in-part of co-pending application having U.S. Ser. No.16/176,137, filed Oct. 31, 2018, which is a continuation in-part ofPCT/US2017/059011 filed Oct. 30, 2017, which claims benefit of U.S.Provisional Application No. 62/464,491, filed Feb. 28, 2017, U.S.Provisional Application No. 62/422,298, filed Nov. 15, 2016, and U.S.Provisional Application No. 62/415,740, filed Nov. 1, 2016, the entirecontents of each of which are incorporated herein by reference.

GOVERNMENT SUPPORT

This invention was made with government support under grant numbersCA15501904, CA163657, HL127522 and CA197098 awarded by the NationalInstitutes of Health. The government has certain rights in theinvention.

INCORPORATION BY REFERENCE OF SEQUENCE LISTING

The Sequence Listing in the ASCII text file, named as050_9147_US_SequenceListing.txt of 15 KB, created on Nov. 4, 2021, andsubmitted to the United States Patent and Trademark Office via EFS-Web,is incorporated herein by reference.

FIELD OF THE DISCLOSURE

The present disclosure is generally directed to nucleic acidcompositions that include 5-halouracil. More specifically, the presentdisclosure provides modified microRNA compositions that contain one ormore 5-halouracil compounds and methods for using the same. Furthermore,the instant application provides pharmaceutical compositions thatinclude the inventive nucleic acid compositions and methods for treatingcancer using the same.

BACKGROUND

MicroRNAs (miRNAs, miRs) are a class of highly conserved, non-codingsmall ribonucleic acid (RNA) molecules that mediate translation in acell or organism by negatively regulating the expression of their targetgenes and thus causing translational arrest, messenger RNA (mRNA)cleavage or a combination thereof. See Bartel D P. Cell. (2009)136(2):215-33. By targeting multiple transcripts, miRNAs regulate a widerange of biological processes including apoptosis, differentiation andcell proliferation; thus, aberrant microRNA function can lead to cancer(see Ambros V. Nature. (2004) 431 pp. 350-355) and as such, miRNAs haverecently been identified as as biomarkers, oncogenes or tumorsuppressors. See, e.g., Croce, C M. Nat Rev Genet. (2009) 10 pp.704-714.

According to the World Health Organization, Cancer is a leading cause ofdeath worldwide, accounting for 8.8 million deaths in 2015. The mostcommon causes of cancer death are cancers of the lung (1.69 milliondeaths), liver (788,000 deaths), colorectal (774,000 deaths), stomach(i.e., gastric cancer) accounting for 774,000 deaths, and breast(754,000 deaths). See Surveillance, Epidemiology, and End ResultsProgram. SEER Cancer Stat Facts. National Cancer Institute. Bethesda,Md. (2018).

Lung cancer is the leading cause of cancer death in both men and womenin the United States, with only 18.6% of patients diagnosed with lungcancer surviving beyond 5 years. Surveillance, Epidemiology, and EndResults Program. SEER Cancer Stat Facts: Lung and Bronchus Cancer.National Cancer Institute. Bethesda, Md. (2018). There are two primarycategories of lung cancer: non-small cell lung cancer and small celllung cancer. Non-small cell lung cancer is further delineated by type ofcancer cells present in a tissue. As such, non-small cell lung cancer isbroken down into following sub-classes of lung cancer: squamous cellcarcinoma (also called epidermoid carcinoma), large cell carcinoma,adenocarcinoma (i.e., cancer that originates in cells lining alveoli),pleomorphic, carcinoid tumor and salivary gland carcinoma. Meanwhile,there are two main types of small cell lung cancer: small cell carcinomaand combined small cell carcinoma. SEER Cancer Stat Facts: Lung andBronchus Cancer. National Cancer Institute. Bethesda, Md. (2018). Themost common treatment for non-small cell lung cancers is gemcitabine(2′, 2′-difluoro 2′deoxycytidine), taxol (e.g., paclitaxel), cisplatin(a DNA cross-linking agent), and combinations thereof. However, manytypes of antibody-based therapeutics are also used to treat non-smallcell lung cancer (e.g., gefitinib, pembrolizumab, alectinib). Small celllung cancer is commonly treated by methotrexate, doxorubicinhydrochloride, and topotecan based chemotherapeutic agents.

Breast cancer is the second most common cancer in women, with the mostcommon he most common type of breast cancer being ductal carcinoma.Ductal carcinoma begins in the cells of the ducts. In contrast, lobularcarcinoma, which is often found in both breasts, originates in the lobesor lobules. Many chemotherapeutic agents are used to treat breast cancerincluding, but not limited to, cytotoxic drugs such as taxols(paclitaxel, docetaxel) doxorubicin hydrochloride, 5-FU, gemcitabinehydrochloride, methotrexate, and tamoxifen citrate. In addition manyantibody-based therapeutic agents are administered to treat varioustypes of breast cancer, such as trastuzumab, olaparib and pertuzumab.Triple Negative Breast Cancers (TNBCs) are defined by lack of expressionof estrogen receptor (ER), progesterone receptor (PR), and humanepidermal growth factor receptor 2 (HER2), and represent approximately15-20% of all total breast cancer cases. [AMD1] These three receptorsare commonly targeted for breast cancer therapy. Unfortunately, TNBCsexclude effective targeted therapeutic options and standard of TNBC careremains chemotherapy. Therefore, TNBC is typically associated with theworst prognosis among all subtypes of breast cancer, due in-part toheterogeneity, high-rates of metastasis to lung, brain and liver, andchemo-resistance. As such, it is critical to develop new effectivetreatments for breast cancer.

Colorectal cancer (CRC) is the third most common malignancy and thesecond most common cancer-related cause of death in the United States.See, Hegde S R, et al., Expert review of gastroenterology & hepatology.(2008) 2(1) pp. 135-49. There are many chemotherapeutic agents used totreat cancer; however pyrimidine antagonists, such asfluoropyrimidine-based chemotherapeutic agents (e.g., 5-fluorouracil,S-1) are the gold standard for treating colorectal cancer. Pyrimidineantagonists, block the synthesis of pyrimidine containing nucleotides(Cytosine and Thymine in DNA; Cytosine and Uracil in RNA). Becausepyrimidine antagonists have similar structures when compared toendogenous nucleotides, they compete with the natural pyrimidines toinhibit crucial enzymatic activity involved in the replication processleading to the prevention of DNA and/or RNA synthesis and inhibition ofcell division.

Gastric cancer (i.e., stomach cancer or gastric adenocarcinoma) is thefourth most common cause of cancer-related death in the world, and itremains difficult to cure in Western countries, primarily because mostpatients present with advanced disease. In the United States, stomachmalignancy is currently the 14th most common cancer. American CancerSociety: Cancer Facts and FIGS. 2018. American Cancer Society. Atlanta,Ga. (2018). Gastric cancers typically present in to forms, intestinaladenocarcinomas, which are well differentiated, or diffuseadenocarcinomas that are poorly differentiated and do not form glandularstructures. Due to a lack of effective non-invasive treatment options,surgery remains the primary treatment for gastric cancers. However, acombination of 5-fluorouracil (5-FU) and leucovorin can also beadministered to gastric cancer patients.

Pancreatic cancer is a deadly cancer that is very difficult to treat.See Siegel, R L et al. Cancer J Clin. (2015) 65 pp. 5-29. Unique aspectsof pancreatic cancer include a very low 5 year survival rate of lessthan 7% (Id.), late presentation, early metastasis and a poor responseto chemotherapy and radiation. See Maitra A and Hruban R H, Annu Rev.Pathol. (2008) 3 pp. 157-188. To date gemcitabine-based chemotherapy(2′, 2′-difluoro 2′deoxycytidine) is the gold standard for the treatmentof pancreatic cancer, however the effect of therapeutic intervention islimited due to drug resistance. Oettle, H et al. JAMA (2013) 310 pp.1473-1481.

Blood born cancers, i.e., leukemia, are a common form of cancer, whichis also very diverse, as evidenced by the number of different types ofleukemia. In 2015, there were an estimated 405,815 people living withleukemia in the United States. The primary types of leukemia are: acutelymphocytic leukemia (ACL), acute lymphoblastic leukemia (ALL), acutemylogenous leukemia (AML), chronic lymphocytic leukemia (CLL) andchronic mylogenous leukemia (CIVIL). Noone A M, et al. (eds). SEERCancer Statistics Review, 1975-2015, National Cancer Institute.Bethesda, Md. (2018). Drugs approved for the treatment of leukemiainclude, for example, doxorubicin hydrochloride, 5-FU, gemcitabinehydrochloride, cytarabine, methotrexate, and tamoxifen citrate,rituximab, ibrutinib, imatinib and dasatinib.

5-fluorouracil (i.e., 5-FU, or more specifically,5-fluoro-1H-pyrimidine-2,4-dione) is a well known pyrimidine antagonistthat is used in many adjuvant chemotherapeutic medicants, such as Carac®cream, Efudex®, Fluoroplex®, and Adrucil®. It is well established that5-FU targets a critical enzyme, thymidylate synthase (TYMS or TS), whichcatalyzes the methylation of deoxyuridine monophosphate (dUMP) todeoxythymidine monophosphate (dTMP) an essential step in DNAbiosynthesis. Danenberg P. V., Biochim. Biophys. Acta. (1977)473(2):73-92. However, despite the steady improvement of 5-FU-basedtherapy, the patient response rate to 5-FU-based chemotherapy remainsmodest, due to the development of drug resistance. Longley D. B, et al.,Apoptosis, Cell Signaling, and Human Diseases, (2007) p. 263-78.

Nevertheless, the existing cancer therapies are still in their infancy,with many hurdles still waiting to be improved or overcome. For example,it is well known that, although fairly efficacious in treating a varietyof cancers, 5-FU possesses substantial toxicity and can elicit a host ofadverse side effects. 5-FU, like many cytotoxic chemotherapeutic agents,is administered systemically by IV or injection and non-specificallytargets all dividing cells in the subject (including cancer cells). Assuch, new targeted anti-cancer therapeutics with less toxicity aresought as an alternative to existing cancer therapeutics.

With respect to miRNAs, these compounds are known to be susceptible toenzymatic degradation when administered, which results in poorstabilities. Moreover, tumor cells have been known to circumventapoptotic pathways by developing resistance to common therapeuticagents, such as 5-FU and gemcitabine. See Gottesman M. M. et al., NatureReviews Cancer, (2002) 2(1):48-58. Thus, there would be a significantbenefit in more efficacious, stable, and less toxic medications for thetreatment of cancer.

SUMMARY OF THE DISCLOSURE

Without being bound by any one particular theory, the present disclosureis premised on the discovery that the incorporation of 5-halouracilbases within the nucleotide sequences of microRNAs increases microRNAefficacy as an anticancer therapeutic agent, when compared to certainknown chemotherapeutic agents alone and/or the native microRNA molecule.The current disclosure demonstrates that nucleic acid compositions(i.e., a microRNA), which incorporate at least one 5-halouracil basehave exceptional efficacy as anti-cancer agents. Moreover, the dataherein shows that contacting a cell with a modified microRNA compositionof the present disclosure regulates cell-cycle progression and reducestumorigenesis by, for example, reducing cancer cell proliferation andincreasing the efficacy of chemotherapeutic agents. Furthermore, it isshown that the modified microRNAs of the present disclosure retaintarget specificity, can be delivered without the use of harmful andineffective delivery vehicles (e.g., nanoparticles), and exhibitenhanced potency and stability without abolishing the natural functionof the endogenous microRNA. Hence the present disclosure provides novelmodified microRNA compositions with enhanced stability and potency,target specificity, and low-toxicity for the treatment of many types ofcancer.

Therefore, in one aspect of the present disclosure nucleic acidcompositions that include a modified microRNA nucleotide sequence havingat least one uracil base (U, U-bases) that has been replaced by a5-halouracil, such as 5-fluorouracil (5-FU) are described. In certainembodiments, the modified microRNA has more than one, or exactly oneuracil that has been replaced by a 5-halouracil. In some embodiments,the modified microRNA nucleotide sequence includes two, three, four,five, six, seven, eight or more uracil bases that have been replaced bya 5-halouracil. In specific embodiments, all of the uracil nucleotidebases of native microRNA have been replaced by a 5-halouracil.

In some embodiments, the 5-halouracil is, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil. In specific embodiments,the 5-halouracil is 5-fluorouracil.

In certain embodiments, the modified microRNA nucleotide sequenceincludes more than one 5-halouracil whereby each of the 5-halouracilsare the same. In other embodiments, the modified microRNA nucleotidesequence includes more than one 5-halouracil whereby each of the5-halouracils is different. In other embodiments, the modified microRNAnucleotide sequence includes more than two 5-halouracils, whereby themodified microRNA nucleotide sequence includes a combination ofdifferent 5-halouracils.

In an exemplary embodiment of the present disclosure, a nucleic acidcomposition that contains a miR-129 nucleotide sequence that has beenmodified by replacing at least one of the uracil nucleotide bases with a5-halouracil is provided. More specifically, the nucleic acidcomposition contains at least the following native miR-129 nucleotidesequence: CUUUUUGCGGUCUGGGCUUGC [SEQ ID NO. 1], wherein at least one,two, three, four, five, six, seven, eight or all of the uracil bases inthe shown nucleic acid sequence or that may be covalently appended tothe shown sequence, are replaced by a 5-halouracil.

In a specific embodiment of the present disclosure, the modifiedmicroRNA has nucleic acid sequence consisting ofCU^(F)U^(F)U^(F)U^(F)U^(F)GCGGU^(F)CU^(F)GGGCU^(F)U^(F)GC [SEQ ID NO.4], wherein U^(F) is a halouracil, specifically 5-fluorouracil.

In other embodiments, a seed portion of the native miR-129 nucleotidesequence, GUUUUUGC remains unmodified (i.e., does not include a5-halouracil) while one or more (or all) of the remaining uracilnucleotide bases in the remainder of the modified miR-129 nucleotidesequence are replaced by an equivalent number of 5-halouracils. In aspecific embodiment, the modified miR-129 microRNA of the presentdisclosure has nucleic acid sequence consisting ofCUUUUUGCGGU^(F)CU^(F)GGGCU^(F)U^(F)GC [SEQ ID NO. 5], whereby U^(F) is ahalouracil, specifically 5-fluorouracil.

In some embodiments, the 5-halouracil is, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil. In specific embodiments,the 5-halouracil is 5-fluorouracil.

In another embodiment of the present disclosure, nucleic acidcompositions that contain a miR-15a nucleotide sequence that has beenmodified by replacing at least one of the uracil nucleotide bases with a5-halouracil, such as 5-fluorouracil (5-FU) are provided. Specifically,the nucleic acid composition contains at least the following nativemiR-15a nucleotide sequence: UAGCAGCACAUAAUGGUUUGUG [SEQ ID NO. 2],wherein at least one, two, three, four, five, six or all of the uracilnucleotide bases in the shown sequence, or that may be covalentlyappended to the shown sequence, are 5-halouracils.

In a specific embodiment of the present disclosure, the modified miR-15amicroRNA has nucleic acid sequence consisting ofU^(F)AGCAGCACAU^(F)AAU^(F)GGU^(F)U^(F)U^(F)GU^(F)G [SEQ ID NO. 6],wherein U^(F) is a halouracil, specifically 5-fluorouracil.

In other embodiments, a seed portion of the native miR-15a nucleotidesequence, UAGCAGCA, remains unmodified with a 5-halouracil, while one ormore (or all) of the remaining uracil bases in the remainder of themiR-15a nucleotide sequence (non-seed portion) are replaced by a5-halouracil.

In a specific embodiment, the modified miR-15a microRNA has nucleic acidsequence consisting of UAGCAGCACAU^(F)AAU^(F)GGU^(F)U^(F)U^(F)GU^(F)G[SEQ ID NO. 7], wherein U^(F) is a halouracil, specifically5-fluorouracil.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a miR-140 nucleotide sequencethat has been modified. In some embodiments, the native miR-140nucleotide sequence has been modified by replacing at least one of the Ubases with a 5-halouracil. More specifically, the nucleic acidcomposition contains at least the following native miR-140 nucleotidesequence: CAGUGGUUUUACCCUAUGGUAG [SEQ ID NO. 8], wherein at least one,two, three, four, five, six, seven or all of the uracil bases in theshown nucleic acid sequence are replaced by a 5-halouracil.

In one set of embodiments, precisely one of the U bases in the nativemiR-140 nucleic acid sequence sequence is a 5-halouracil. In a secondset of embodiments, precisely or at least two U bases in the nativemiR-140 nucleotide sequence are replaced by 5-halouracils. In anotherset of embodiments, precisely or at least three U bases in the miR-140nucleotide sequence are 5-halouracils. In other embodiments, preciselyor at least four U bases in the native miR-140 nucleotide sequence are5-halouracils. In some embodiments, precisely or at least five U basesin the miR-140 nucleotide sequence are 5-halouracils. In a yet otherembodiments, precisely or at least six U bases in the miR-140 nucleotidesequence are 5-halouracils. In some embodiments, precisely or at leastseven U bases in the miR-140 nucleotide sequence are 5-halouracils. Inspecific embodiments, all of the U bases in the miR-140 nucleotidesequence, whether in the native and/or in an appended portion, are5-halouracils.

In an exemplary embodiment, the modified microRNA nucleic acidcomposition of the present disclosure has a nucleotide sequence ofCAGU^(F)GGUUUUACCCU^(F)AUGGU^(F)AG [SEQ ID NO. 9], wherein U^(F) is ahalouracil, specifically 5-fluorouracil.

In yet another embodiment, the modified microRNA nucleic acidcomposition of the present disclosure has a nucleotide sequence ofCAGU^(F)GGU^(F)U^(F)U^(F)U^(F)ACCCU^(F)AU^(F)GGU^(F) AG [SEQ ID NO. 16],wherein U^(F) is a halouracil, specifically 5-fluorouracil.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a modified native miR-192 ormiR-215 nucleotide sequence that has been modified by replacing at leastone of the uracil bases with a 5-halouracil. In some embodiments, themodified miR-192 nucleotide sequence has been modified by replacing atleast one of the U bases with a 5-fluorouracil. More specifically, thenucleic acid composition contains at least the following native miR-192nucleotide sequence: CUGACCUAUGAAUUGACAGCC [SEQ ID NO. 10], wherein atleast one, two, three, four or all of the uracil bases in the shownnucleic acid sequence are replaced by a 5-halouracil.

In specific embodiments, precisely one of the U bases in the modifiedmiR-192 nucleotide sequence is a 5-halouracil. In other embodiments,precisely or at least two U bases in the modified miR-192 nucleotidesequence are 5-halouracils. In another set of embodiments, precisely orat least three U bases in the modified miR-192 nucleotide sequence are5-halouracils. In other embodiments, precisely or at least four U basesin the modified miR-192 or miR-215 nucleotide sequence are5-halouracils. In specific embodiments, all of the U bases in themodified miR-192 or miR-215 sequence, whether in the native and/or in anappended portion of the nucleic acid, are 5-halouracils.

In an exemplary embodiment, the nucleic acid composition of the presentdisclosure has a modified miR-192 or modified miR-215 nucleotidesequence of CU^(F)GACCU^(F)AU^(F)GAAU^(F)U^(F)GACAGCC [SEQ ID NO. 11],wherein U^(F) is a halouracil, specifically 5-fluorouracil.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a modified native miR-502nucleotide sequence that has been modified by replacing uracil with5-halouracil. In some embodiments, the modified miR-502 nucleotidesequence has been modified by replacing at least one of the U bases witha 5-fluorouracil. More specifically, the nucleic acid compositioncontains at least the following native miR-502 nucleotide sequence:AUCCUUGCUAUCUGGGUGCUA [SEQ ID NO. 12], wherein at least one, two, three,four, five, six, seven or all of the uracil bases in the shown nucleicacid sequence are replaced by a 5-halouracil.

In another set of embodiments, precisely one of the U bases in themiR-502 nucleotide sequence is a 5-halouracil. In a second set ofembodiments, precisely or at least two U bases in the miR-502 nucleotidesequence are 5-halouracils. In another set of embodiments, precisely orat least three U bases in the miR-502 nucleotide sequence are5-halouracils. In other embodiments, precisely or at least four U basesin the miR-502 nucleotide sequence are 5-halouracils. In otherembodiments, precisely or at least five U bases in the miR-502nucleotide sequence are 5-halouracils. In other embodiments, preciselyor at least six U bases in the modified miR-502 nucleotide sequence are5-halouracils. In other embodiments, precisely or at least seven U basesin the miR-502 nucleotide sequence are 5-halouracils. In specificembodiments, all of the U bases in the miR-502 nucleotide sequence,whether in the native and/or in an appended portion, are 5-halouracils.

In an exemplary embodiment, the modified miR-502 nucleic acidcomposition of the present disclosure has a modified nucleotide sequenceof AU^(F)CCU^(F)U^(F)GCUAU^(F)CU^(F)GGGU^(F)GCU^(F)A [SEQ ID NO. 13],wherein U^(F) is a halouracil, specifically 5-fluorouracil.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a modified miR-506 nucleotidesequence that includes a 5-halouracil. In some embodiments, the modifiedmiR-506 nucleotide sequence has been modified by replacing at least oneof the U bases with a 5-halouracil, such as 5-fluorouracil. Forinstance, the nucleic acid composition can contain at least thefollowing native miR-506 nucleotide sequence: UAUUCAGGAAGGUGUUACUUAA[SEQ ID NO. 14], wherein at least one, two, three, four, five, six,seven or all of the uracil bases in the shown nucleic acid sequence arereplaced by a 5-halouracil.

In another set of embodiments, precisely one of the U bases in thenative miR-506 nucleotide sequence is replaced by a 5-halouracil. In asecond set of embodiments, precisely or at least two U bases in themodified miR-506 nucleotide sequence are 5-halouracils. In another setof embodiments, precisely or at least three U bases in the modifiedmiR-506 nucleotide sequence are 5-halouracils. In other embodiments,precisely or at least four U bases in the modified miR-506 nucleotidesequence are 5-halouracils. In other embodiments, precisely or at leastfive U bases in the modified miR-506 nucleotide sequence are5-halouracils. In other embodiments, precisely or at least six U basesin the modified miR-506 nucleotide sequence are 5-halouracils. In otherembodiments, precisely or at least seven U bases in the modified miR-506nucleotide sequence are 5-halouracils. In specific embodiments, all ofthe U bases in the modified miR-506 nucleotide sequence, whether in thenative and/or in an appended portion, are 5-halouracils.

In an exemplary embodiment, the miR-506 nucleic acid composition of thepresent disclosure has a modified microRNA nucleotide sequence ofU^(F)AU^(F)U^(F)CAGGAAGGU^(F)GU^(F)U^(F)ACU^(F)U^(F)AA [SEQ ID NO. 15],wherein U^(F) is a halouracil, specifically 5-fluorouracil.

In yet another embodiment, the present disclosure provides nucleic acidcompositions that include a modified miR-34 nucleotide sequence thatincludes a 5-halouracil. In some embodiments, the modified miR-34nucleotide sequence has been modified by replacing at least one of the Ubases with a 5-halouracil, such as 5-fluorouracil. For instance, thenucleic acid composition can contain at least the following nativemiR-34 nucleotide sequence: UGGCAGUGUCUUAGCUGGUUGU [SEQ ID NO. 17],wherein at least one, two, three, four, five, six, seven, eight or allof the uracil bases in the shown nucleic acid sequence are replaced by a5-halouracil.

In another set of embodiments, precisely one of the U bases in thenative miR-34 nucleotide sequence is replaced by a 5-halouracil. In asecond set of embodiments, precisely or at least two U bases in themodified miR-34 nucleotide sequence are 5-halouracils. In another set ofembodiments, precisely or at least three U bases in the modified miR-34nucleotide sequence are 5-halouracils. In other embodiments, preciselyor at least four U bases in the modified miR-34 nucleotide sequence are5-halouracils. In other embodiments, precisely or at least five U basesin the modified miR-34 nucleotide sequence are 5-halouracils. In otherembodiments, precisely or at least six U bases in the modified miR-34nucleotide sequence are 5-halouracils. In other embodiments, preciselyor at least seven U bases in the modified miR-34 nucleotide sequence are5-halouracils. In other embodiments, precisely or at least eight U basesin the modified miR-34 nucleotide sequence are 5-halouracils. Inspecific embodiments, all of the U bases in the modified miR-34nucleotide sequence, whether in the native and/or in an appendedportion, are 5-halouracils.

In an exemplary embodiment, the miR-34 nucleic acid composition of thepresent disclosure has a modified microRNA nucleotide sequence ofU^(F)GGCAGU^(F)GU^(F)CU^(F)U^(F)AGCU^(F)GGU^(F)U^(F)GU^(F) [SEQ ID NO.18], wherein U^(F) is a halouracil, specifically 5-fluorouracil.

In yet another embodiment, the present disclosure provides nucleic acidcompositions that include a modified miR-200a nucleotide sequence thatincludes a 5-halouracil. In some embodiments, the modified miR-200anucleotide sequence has been modified by replacing at least one of the Ubases with a 5-halouracil, such as 5-fluorouracil. For instance, thenucleic acid composition can contain at least the following nativemiR-200a nucleotide sequence: UAACACUGUCUGGUAACGAUGU [SEQ ID NO. 19],wherein at least one, two, three, four, five, six, or all of the uracilbases in the shown nucleic acid sequence are replaced by a 5-halouracil.

In another set of embodiments, precisely one of the U bases in thenative miR-200a nucleotide sequence is replaced by a 5-halouracil. In asecond set of embodiments, precisely or at least two U bases in themodified miR-200a nucleotide sequence are 5-halouracils. In another setof embodiments, precisely or at least three U bases in the modifiedmiR-200a nucleotide sequence are 5-halouracils. In other embodiments,precisely or at least four U bases in the modified miR-200a nucleotidesequence are 5-halouracils. In other embodiments, precisely or at leastfive U bases in the modified miR-200a nucleotide sequence are5-halouracils. In other embodiments, precisely or at least six U basesin the modified miR-200a nucleotide sequence are 5-halouracils. Inspecific embodiments, all of the U bases in the modified miR-200anucleotide sequence, whether in the native and/or in an appendedportion, are 5-halouracils.

In an exemplary embodiment, the miR-200a nucleic acid composition of thepresent disclosure has a modified microRNA nucleotide sequence ofU^(F)AACACU^(F)GU^(F)CU^(F)GGU^(F)AACGAU^(F)GU^(F) [SEQ ID NO. 20],wherein U^(F) is a halouracil, specifically 5-fluorouracil.

In other embodiments, the present disclosure provides nucleic acidcompositions that include a modified miR-200b nucleotide sequence thatincludes a 5-halouracil. In some embodiments, the modified miR-200bnucleotide sequence has been modified by replacing at least one of the Ubases with a 5-halouracil, such as 5-fluorouracil. For instance, thenucleic acid composition can contain at least the following nativemiR-200b nucleotide sequence: UAAUACUGCCUGGUAAUGAUGA [SEQ ID NO. 21],wherein at least one, two, three, four, five, six, or all of the uracilbases in the shown nucleic acid sequence are replaced by a 5-halouracil.

In another set of embodiments, precisely one of the U bases in thenative miR-200b nucleotide sequence is replaced by a 5-halouracil. In asecond set of embodiments, precisely or at least two U bases in themodified miR-200b nucleotide sequence are 5-halouracils. In another setof embodiments, precisely or at least three U bases in the modifiedmiR-200b nucleotide sequence are 5-halouracils. In other embodiments,precisely or at least four U bases in the modified miR-200b nucleotidesequence are 5-halouracils. In other embodiments, precisely or at leastfive U bases in the modified miR-200b nucleotide sequence are5-halouracils. In other embodiments, precisely or at least six U basesin the modified miR-200b nucleotide sequence are 5-halouracils. Inspecific embodiments, all of the U bases in the modified miR-200bnucleotide sequence, whether in the native and/or in an appendedportion, are 5-halouracils.

In an exemplary embodiment, the miR-200b nucleic acid composition of thepresent disclosure has a modified microRNA nucleotide sequence ofU^(F)AAU^(F)ACU^(F)GCCU^(F)GGU^(F)AAU^(F)GAU^(F)GA [SEQ ID NO. 22],wherein U^(F) is a halouracil, specifically 5-fluorouracil.

In yet another embodiment, the present disclosure provides nucleic acidcompositions that include a modified miR-200c nucleotide sequence thatincludes a 5-halouracil. In some embodiments, the modified miR-200cnucleotide sequence has been modified by replacing at least one of the Ubases with a 5-halouracil, such as 5-fluorouracil. For instance, thenucleic acid composition can contain at least the following nativemiR-200c nucleotide sequence: UAAUACUGCCGGGUAAUGAUGGA [SEQ ID NO. 23],wherein at least one, two, three, four, five or all of the uracil basesin the shown nucleic acid sequence are replaced by a 5-halouracil.

In another set of embodiments, precisely one of the U bases in thenative miR-200c nucleotide sequence is replaced by a 5-halouracil. In asecond set of embodiments, precisely or at least two U bases in themodified miR-200c nucleotide sequence are 5-halouracils. In another setof embodiments, precisely or at least three U bases in the modifiedmiR-200c nucleotide sequence are 5-halouracils. In other embodiments,precisely or at least four U bases in the modified miR-200c nucleotidesequence are 5-halouracils. In other embodiments, precisely or at leastfive U bases in the modified miR-200c nucleotide sequence are5-halouracils. In specific embodiments, all of the U bases in themodified miR-200c nucleotide sequence, whether in the native and/or inan appended portion, are 5-halouracils.

In an exemplary embodiment, the miR-200c nucleic acid composition of thepresent disclosure has a modified microRNA nucleotide sequence ofU^(F)AAU^(F)ACU^(F)GCCGGGU^(F)AAU^(F)GAU^(F)GGA [SEQ ID NO. 24], whereinU^(F) is a halouracil, specifically 5-fluorouracil.

In some embodiments, the present disclosure provides nucleic acidcompositions that include a modified miR-145 nucleotide sequence thatincludes a 5-halouracil. In one instance, the modified miR-145nucleotide sequence has been modified by replacing at least one of the Ubases with a 5-halouracil, such as 5-fluorouracil. For example, thenucleic acid composition can contain at least the following nativemiR-145 nucleotide sequence: GUCCAGUUUUCCCAGGAAUCCCU [SEQ ID NO. 25],wherein at least one, two, three, four, five, six, or all of the uracilbases in the shown nucleic acid sequence are replaced by a 5-halouracil.

In another set of embodiments, precisely one of the U bases in thenative miR-145 nucleotide sequence is replaced by a 5-halouracil. In asecond set of embodiments, precisely or at least two U bases in themodified miR-145 nucleotide sequence are 5-halouracils. In another setof embodiments, precisely or at least three U bases in the modifiedmiR-145 nucleotide sequence are 5-halouracils. In other embodiments,precisely or at least four U bases in the modified miR-145 nucleotidesequence are 5-halouracils. In other embodiments, precisely or at leastfive U bases in the modified miR-145 nucleotide sequence are5-halouracils. In other embodiments, precisely or at least six U basesin the modified miR-145 nucleotide sequence are 5-halouracils. Inspecific embodiments, all of the U bases in the modified miR-145nucleotide sequence, whether in the native and/or in an appendedportion, are 5-halouracils.

In an exemplary embodiment, the miR-145 nucleic acid composition of thepresent disclosure has a modified microRNA nucleotide sequence ofGU^(F)CCAGU^(F)U^(F)U^(F)U^(F)CCCAGGAAU^(F)CCCU^(F) [SEQ ID NO. 26],wherein U^(F) is a halouracil, specifically 5-fluorouracil.

In another exemplary embodiment, nucleic acid compositions are providedthat include a modified native miR-194 nucleotide sequence that has beenmodified by replacing at least one of the uracil bases with a5-halouracil. In some embodiments, the modified miR-194 nucleotidesequence has been modified by replacing at least one of the U bases witha 5-fluorouracil. More specifically, the nucleic acid compositioncontains at least the following native miR-194 nucleotide sequence:UGUAACAGCAACUCCAUGUGGA [SEQ ID NO. 27], wherein at least one, two,three, four or all of the uracil bases in the shown nucleic acidsequence are replaced by a 5-halouracil.

In specific embodiments, precisely one of the U bases in the modifiedmiR-194 nucleotide sequence is a 5-halouracil. In another ofembodiments, precisely or at least two U bases in the modified miR-194nucleotide sequence are 5-halouracils. In another set of embodiments,precisely or at least three U bases in the modified miR-194 nucleotidesequence are 5-halouracils. In other embodiments, precisely or at leastfour U bases in the modified miR-194 nucleotide sequence are5-halouracils. In specific embodiments, all of the U bases in themodified miR-194 sequence, whether in the native and/or in an appendedportion of the nucleic acid, are 5-halouracils.

In an exemplary embodiment, the nucleic acid composition of the presentdisclosure has a modified miR-194 nucleotide sequence ofU^(F)GU^(F)AACAGCAACU^(F)CCAU^(F)GU^(F)GGA [SEQ ID NO. 28], whereinU^(F) is a halouracil, specifically 5-fluorouracil.

In yet another embodiment, the present disclosure provides nucleic acidcompositions that include a modified miR-let-7 nucleotide sequence thatincludes a 5-halouracil. In some embodiments, the modified miR let-7nucleotide sequence has been modified by replacing at least one of the Ubases with a 5-halouracil, such as 5-fluorouracil. For instance, thenucleic acid composition can contain at least the following nativemiR-let-7 nucleotide sequence: UGAGGUAGUAGGUUGUAUAGUU [SEQ ID NO. 29],wherein at least one, two, three, four, five, six, seven, eight or allof the uracil bases in the shown nucleic acid sequence are replaced by a5-halouracil.

In another set of embodiments, precisely one of the U bases in thenative miR-let-7 nucleotide sequence is replaced by a 5-halouracil. In asecond set of embodiments, precisely or at least two U bases in themodified miR-let-7 nucleotide sequence are 5-halouracils. In another setof embodiments, precisely or at least three U bases in the modifiedmiR-34 nucleotide sequence are 5-halouracils. In other embodiments,precisely or at least four U bases in the modified miR-let-7 nucleotidesequence are 5-halouracils. In other embodiments, precisely or at leastfive U bases in the modified miR-let-7 nucleotide sequence are5-halouracils. In other embodiments, precisely or at least six U basesin the modified miR-let-7 nucleotide sequence are 5-halouracils. Inother embodiments, precisely or at least seven U bases in the modifiedmiR-let-7 nucleotide sequence are 5-halouracils. In other embodiments,precisely or at least eight U bases in the modified miR-let-7nucleotidesequence are 5-halouracils. In specific embodiments, all of the U basesin the modified miR-let-7nucleotide sequence, whether in the nativeand/or in an appended portion, are 5-halouracils.

In an exemplary embodiment, the miR-let-7 nucleic acid composition ofthe present disclosure has a modified microRNA nucleotide sequence ofU^(F)GAGGU^(F)AGU^(F)AGGU^(F)U^(F)GU^(F)AU^(F)AGU^(F)U^(F) [SEQ ID NO.30], wherein U^(F) is a halouracil, specifically 5-fluorouracil.

In another embodiment, the present disclosure provides nucleic acidcompositions that include a modified miR-489 nucleotide sequenceincluding a 5-halouracil. In certain embodiments, the modified miR-489nucleotide sequence has been modified by replacing at least one of the Ubases in the native microRNA sequence with a 5-halouracil, such as5-fluorouracil. For instance, the exemplary modified miR-489 nucleicacid composition can contain at least the following native miR-489nucleotide sequence, from 3′ to 5′: CGACGGCAUAUACACUACAGUG [SEQ ID NO.31], wherein at least one, two, three, or all of the uracil bases in themiR-489 nucleic acid sequence are replaced by a 5-halouracil.

In some embodiments, precisely one of the U bases in the native miR-489nucleotide sequence is replaced by a 5-halouracil. In other embodiments,precisely or at least two U bases in a modified miR-489 nucleotidesequence are 5-halouracils. In another embodiment, precisely or at leastthree U bases in the modified miR-489 nucleotide sequence are5-halouracils. In other embodiments, precisely four (i.e., all) U basesin the modified miR-489 nucleotide sequence are 5-halouracils.

In a specific embodiment, all of the U bases in the modified miR-489nucleotide sequence, whether in the native and/or in an appendedportion, are 5-halouracils, such as fluorouracil.

In an exemplary embodiment, the modified miR-489 nucleic acidcomposition of the present disclosure has a modified microRNA nucleotidesequence of CGACGGCAU^(F)AU^(F)ACACU^(F)ACAGU^(F)G [SEQ ID NO. 32],wherein U^(F) is a halouracil, specifically 5-fluorouracil.

In some embodiments, the 5-halouracil is, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil. In specific embodiments,the 5-halouracil is 5-fluorouracil, or a combination thereof. In certaininstances, all of the U-bases of the modified miR are substituted with a5-fluorouracil.

The present disclosure is also directed to formulations of a modifiedmicroRNA composition described herein or a formulation that includescombinations thereof, i.e., at least two modified microRNAs. In certainembodiments, the formulations can include pharmaceutical preparationsthat comprise the above-described nucleic acid compositions and otherknown pharmacological agents, such as one or more pharmaceuticallyacceptable carriers.

The present disclosure reveals that the modified microRNAs each exhibita potent efficacy as an anti-cancer therapeutic. Notably, each of themodified microRNA nucleic acid compositions tested reduce cancer cellproliferation, tumor growth and development in a dose dependent mannerby inducing cell-cycle arrest in all six cancer types examined.

Therefore, another aspect of the present disclosure is directed to amethod for treating cancer that includes administering to a subject aneffective amount of one or more of nucleic acid compositions describedherein. In certain embodiments of the present methods, the nucleic acidcompositions include a modified miR-129, miR-15a, miR-192/miR-215,miR-140, miR-502, miR-506, miR-34, miR-200a, miR-200b, miR-200c,miR-145, miR-194, miR-let-7, miR-489 nucleotide sequence or acombination thereof, wherein at least one, two, three, four, or more ofthe uracil nucleotide bases in each of the native (unmodified)nucleotide sequences have been replaced by a 5-halouracil.

In specific embodiments, the present methods include administering anucleic acid composition of the present disclosure to a subject havingcancer or a predisposition to cancer, whereby the nucleic acidcomposition is a modified miR-129 or a modified miR-15a nucleic acid. Ina specific embodiment of the present disclosure, the modified microRNAadministered has nucleic acid sequence selected from the groupconsisting of

[SEQ ID NO. 4]CU^(F)U^(F)U^(F)U^(F)U^(F)GCGGU^(F)CU^(F)GGGCU^(F)U^(F)GC,[SEQ ID NO. 5] CUUUUUGCGGU^(F)CU^(F)GGGCU^(F)U^(F)GC, [SEQ ID NO. 6]U^(F)AGCAGCACAU^(F)AAU^(F)GGU^(F)U^(F)U^(F)GU^(F)G, and [SEQ ID NO. 7]UAGCAGCACAU^(F)AAU^(F)GGU^(F)U^(F)U^(F)GU^(F)G.

In other embodiments, the present methods include administering anucleic acid composition of the present disclosure to a subject havingcancer or a predisposition to cancer, whereby the nucleic acidcomposition is a modified miR-140 or a modified miR-192 nucleic acid. Ina specific embodiment of the present disclosure, the modified microRNAadministered has nucleic acid sequence selected from the groupconsisting of

[SEQ ID NO. 9] CAGU^(F)GGUUUUACCCU^(F)AUGGU^(F)AG, [SEQ ID NO. 16]CAGU^(F)GGU^(F)U^(F)U^(F)U^(F)ACCCU^(F)AU^(F)GGU^(F)AG, and[SEQ ID NO. 11] CU^(F)GACCU^(F)AU^(F)GAAU^(F)U^(F)GACAGCC.

In another embodiment, the present methods include administering anucleic acid composition of the present disclosure to a subject havingcancer or a predisposition to cancer, whereby the nucleic acidcomposition is a modified miR-502 or a modified miR-506 nucleic acid. Ina specific embodiment of the present disclosure, the modified microRNAadministered has nucleic acid sequence selected from the groupconsisting of

[SEQ ID NO. 13] AU^(F)CCU^(F)U^(F)GCUAU^(F)CU^(F)GGGU^(F)GCU^(F)A, and[SEQ ID NO. 15] U^(F)AU^(F)U^(F)CAGGAAGGU^(F)GU^(F)U^(F)ACU^(F)U^(F)AA.

In another embodiment, the present methods include administering anucleic acid composition of the present disclosure to a subject havingcancer or a predisposition to cancer, whereby the nucleic acidcomposition includes a modified miR-34, a modified miR-145, a modifiedmiR-200a, a modified miR-200b, a modified miR-200c, a modified miR-194or a modified miR-let-7 nucleic acid. In a specific embodiment of thepresent disclosure, the modified microRNA administered has nucleic acidsequence selected from the group consisting ofU^(F)GGCAGU^(F)GU^(F)CU^(F)U^(F)AGCU^(F)GGU^(F)U^(F)GU^(F) [SEQ ID NO.18], U^(F)AACACU^(F)GU^(F)CU^(F)GGU^(F)AACGAU^(F)GU^(F) [SEQ ID NO. 20],U^(F)AAU^(F)ACU^(F)GCCU^(F)GGU^(F)AAU^(F)GAU^(F)GA [SEQ ID NO. 22],U^(F)AAU^(F)ACU^(F)GCCGGGU^(F)AAU^(F)GAU^(F)GGA [SEQ ID NO. 24],GU^(F)CCAGU^(F)U^(F)U^(F)U^(F)CCCAGGAAU^(F)CCCU^(F) [SEQ ID NO. 26],U^(F)GU^(F)AACAGCAACU^(F)CCAU^(F)GU^(F)GGA [SEQ ID NO. 28],U^(F)GAGGU^(F)AGU^(F)AGGU^(F)U^(F)GU^(F)AU^(F)AGU^(F)U^(F) [SEQ ID NO.30], and a combination thereof.

In some embodiments, the present methods include administering a nucleicacid composition of the present disclosure to a subject having cancer ora predisposition to cancer, whereby the nucleic acid composition is amodified miR-489 or a modified miR-200b nucleic acid. In one embodiment,a modified miR-489 and/or a modified miR-200b nucleic acid isadministered to a subject having breast cancer. In a specific embodimentof the present disclosure, the modified microRNA administered hasnucleic acid sequence selected from the group consisting ofCGACGGCAU^(F)AU^(F)ACACU^(F)ACAGU^(F)G [SEQ ID NO. 32], andU^(F)AAU^(F)ACU^(F)GCCU^(F)GGU^(F)AAU^(F)GAU^(F)GA [SEQ ID NO. 22].

In one embodiment, a modified miR-489 nucleic acid composition with thenucleic acid sequence CGACGGCAU^(F)AU^(F)ACACU^(F)ACAGU^(F)G [SEQ ID NO.32] or a pharmaceutical formulation thereof is administered to a subjectdiagnosed with triple negative breast cancer.

In a certain embodiments of the present disclosure, a modified miR-200bnucleic acid composition having the nucleotide sequenceU^(F)AAU^(F)ACU^(F)GCCU^(F)GGU^(F)AAU^(F)GAU^(F)GA [SEQ ID NO. 22] isadministered to a subject with breast cancer, such as triple negativebreast cancer.

In some instances, the subject being treated by the present methods is amammal. In certain embodiments, the subject being treated is a human,dog, horse, pig, mouse, or rat. In a specific embodiment, the subject isa human that has been diagnosed with cancer, or has been identified ashaving a predisposition to developing cancer. In some embodiments, thecancer being treated can be, for example, colorectal, stomach,esophageal, lung, ovarian cancer, pancreatic, or cervical cancer.

In certain embodiments, the methods of the present disclosure treat asubject for one or more of the following types of cancer: colorectalcancer, gastric cancer, pancreatic cancer, lung cancer, blood cancer(e.g., leukemia) or breast cancer.

In one embodiment, the methods of the present disclosure areadministered to a subject with breast cancer such as, for example,triple negative breast cancer, ductal carcinoma, or lobular carcinoma.

The data provided herein surprisingly shows an increased potency of themodified microRNAs described herein when compared to known anticanceragents, such as 5-FU alone in several different cancer models, includingcolorectal cancer, breast cancer, pancreatic cancer, and lung cancer.For example, the present disclosure provides the unexpected finding thatthe described modified nucleic acid compositions are substantially morepotent in inhibiting cancer progression and tumorigenesis than 5-FUalone, or than a combination of 5-FU and any of the following nativemicroRNAs: miR-15a, miR-129, miR-140, miR-192, miR-215, miR-502,miR-506, miR-34, miR-145, miR-200a, miR-200b, miR-200c, miR-194, miR-489or miR-let-7.

As such, the present compositions and methods provide the additionalbenefit of permitting a lower dosing, which results in lower toxicityand fewer side effects. A further significant advantage exhibited by thedescribed nucleic acid compositions is that the instant compositionshave significantly improved efficacy compared to native miR-15a,miR-129, miR-140, miR-192, miR-215, miR-502, miR-506, miR-34, miR-145,miR-200a, miR-200b, miR-200c, miR-194, miR-489 or miR-let-7 nucleicacids that have not been modified with a halouracil. Thus, at least inview of the noted advantages, the nucleic acid compositions disclosedherein represent a substantial advance in the treatment of all cancers.

BRIEF DESCRIPTION OF THE DRAWINGS

The file of this patent contains at least one drawing executed in color.Copies of this patent with color drawing(s) will be provided by thePatent and Trademark Office upon request and payment of the necessaryfee.

FIGS. 1A-1Q. Chemical representation of exemplary modified microRNAnucleotide sequences of the present disclosure. (A) Chemicalrepresentation of miR-129 nucleotide sequence in which all U bases arereplaced by a halouracil (i.e., U^(F)), as set forth in SEQ ID NO: 4.(B) Chemical representation of miR-129 in which only the non-seedportion of miR-129 has U bases replaced with halouracils), as set forthin SEQ ID NO: 5. (C) Chemical representation of miR-15a nucleotidesequence in which all U bases are replaced with a halouracil), as setforth in SEQ ID NO: 6. (D) Chemical representation of miR-15a in whichonly the non-seed portion of miR-15a has U bases replaced withhalouracils), as set forth in SEQ ID NO: 7. (E) Chemical representationof the miR-140 nucleotide sequence in which certain (3) U bases arereplaced by a halouracil as set forth in SEQ ID NO: 9. (F) Chemicalrepresentation of a modified miR-140 nucleotide sequence in whichcertain all U bases are replaced by a halouracil as set forth in SEQ IDNO: 16. (G) Chemical representation of the miR-192 nucleotide sequencein which certain (5) U bases are replaced by a halouracil as set forthin SEQ ID NO: 11. (H) Chemical representation of the miR-502 nucleotidesequence in which certain (7) U bases are replaced by a halouracil asset forth in SEQ ID NO: 13. (I) Chemical representation of the miR-506nucleotide sequence in which all (i.e., 8) U bases are replaced by ahalouracil as set forth in SEQ ID NO: 15. (J) Chemical representation ofthe modified miR-34 nucleotide sequence in which all (i.e., 9) U basesare replaced by a halouracil as set forth in SEQ ID NO: 18. (K) Chemicalrepresentation of the modified miR-200a nucleotide sequence in which all(i.e., 7) U bases are replaced by a halouracil as set forth in SEQ IDNO: 20. (L) Chemical representation of the modified miR-200b nucleotidesequence in which all (i.e., 7) U bases are replaced by a halouracil asset forth in SEQ ID NO: 22. (M) Chemical representation of the modifiedmiR-200c nucleotide sequence in which all (i.e., 6) U bases are replacedby a halouracil as set forth in SEQ ID NO: 24. (N) Chemicalrepresentation of the modified miR-145 nucleotide sequence in which all(i.e., 7) U bases are replaced by a halouracil as set forth in SEQ IDNO: 26. (0) Chemical representation of the modified miR-194 nucleotidesequence in which all (i.e., 5) U bases are replaced by a halouracil asset forth in SEQ ID NO: 28. (P) Chemical representation of the modifiedmiR-let-7 nucleotide sequence in which all (i.e., 9) U bases arereplaced by a halouracil as set forth in SEQ ID NO: 30. (Q) Chemicalrepresentation of the modified miR-489 nucleotide sequence in which all(i.e., 4) U bases are replaced by a halouracil as set forth in SEQ IDNO: 32. The orientation of each exemplary modified microRNA depicted isprovided by a 5′ to 3′ or 3′ to 5′ designation as indicated.

FIGS. 2A-2C. Exemplary modified microRNA nucleic acids enter cancercells and effectively reduce target protein expression. (A) Graphshowing target (E2F3) specificity and the ability of an exemplarymodified miR-129 (with all U bases replaced with 5-FU, 5-FU-miR-129)compared to that of control miRNA, and an unmodified miR-129 nucleicacid. (B) A quantitative Real-Time PCR analysis showing that modifiedmiR-129 nucleic acids (mimic) enter cancer cells. (C) Modified miR-129nucleic acids (mimic) enter a cancer cell and break downs TS-FdUMPsignificantly better than 5-FU alone.

FIG. 3. Graphs showing inhibition of colon cancer cell proliferation in4 different colon cancer cell lines (HCT116, RKO, SW480 and SW620) by anexemplary modified microRNA (mimic). An exemplary modified miR-129nucleic acid having all U bases replaced by 5-flurouracil (- -●- -), ascompared to a non-specific (Negative control, -●-) control andexogenously expressed native miR-129 (◯).

FIG. 4. Combination therapy with 5-FU and modified microRNA compositionsof the present disclosure effectively inhibit cancer cell proliferation.Graphical comparison of colon cancer cell proliferation for cancer cellstreated with a negative control (NC), exogenously expressed nativemiR-129 (miR-129), 5-FU, an exemplary modified miR-129 nucleic acid ofthe present disclosure (5-FU-miR-129), and a combination of 5-FU and theexemplary miR-129 nucleic acid of the present disclosure(5-FU-miR-129+5-FU).

FIGS. 5A-5B. Exemplary modified microRNAs induce apoptosis in coloncancer cells and cause cell cycle arrest. (A) Cell death was quantifiedby FITC-Annexin V apoptosis assay to show that modified miR-129 nucleicacid compositions of the present disclosure induce cancer cell apoptosisat significantly higher levels than negative controls, or ectopicallyexpressed native miR-129 in several different colorectal cancer celllines. (B) Flow cytometry was conducted to reveal that modified miR-129nucleic acid compositions (Mimic-1) of the present disclosure increaseG1 cell cycle arrest at significantly higher levels than negativecontrols, or ectopically expressed native miR-129.

FIG. 6. Modified microRNA nucleic acid compositions of the presentdisclosure eliminate chemotherapy resistant cancer stem cells. HCT116derived colon cancer stem cells were treated with increasingconcentrations of exemplary modified miR-129 nucleic acids of thepresent disclosure (◯) or 5-FU (●). Results show that modified miR-129nucleic acids killed 5-FU resistance cancer stem cells in a dosedependent manner.

FIG. 7. In vivo systemic treatment with exemplary modified microRNAnucleic acid compositions inhibits colon cancer metastasis without toxicside effects. A colon cancer metastasis mouse model was established viatail vein injection of metastatic human colon cancer cells. Two weeksafter establishing metastasis, 40 μg of a modified miR-129 nucleic acidcomposition, as set forth in SEQ ID NO: 4 was delivered by intravenousinjection with a treatment frequency of one injection every other dayfor two weeks. The exemplary modified miR-129 nucleic acid (mimic) wasable to inhibit colon cancer metastasis (right panels) while negativecontrol miRNA (left panels) had no effect. Mice treated with modifiedmiR-129 nucleic acid did not exhibit any toxicity.

FIGS. 8A-8B. Anti cancer activity of a second exemplary modifiedmicroRNA of the present disclosure. (A) Representative western blotscomparing the ability of exogenously expressed unmodified miR-15a(miR-15a) and a modified miR-15a nucleic acid composition (mimic-1) tomodulate protein expression in colon cancer cells. Modified miR-15a, asset forth in SEQ ID NO: 6 (mimic-1) retains the ability to regulatemiR-15a targets (YAP1, BMI-1, DCLK1 and BCL2) and break downs TS-FdUMPin colorectal cancer cells. (B) Modified miR-15a (mimic-1) showedenhanced ability to inhibit colon cancer cell proliferation in threedifferent colorectal cancer cell lines (HCT116, RKO, SW620) compared toexogenously expressed unmodified miR-15a (miR-15a).

FIGS. 9A-9B. Modified microRNA nucleic acids induce cell cycle arrest atthe G1/S phase in leukemia cells and colorectal cancer cells. (A) Graphshowing cell cycle control for control (Negative), unmodified miR-15a(miR-15a) and an exemplary modified miR-15a nucleic acid composition asset forth in SEQ ID NO: 6 (mimic-1). Administration of modified miR-15anucleic acid induced cell cycle arrest compared to unmodified miR-15a asshown by an increased G1/S ratio exhibited by colorectal cancer cellsexpressing modified miR-15a when compared to cells exogenouslyexpressing native miR-15a and negative controls. (B) Additionalexemplary modified microRNA nucleic acids (5-FU-miR-145 and5-FU-miR-let-7) also induce cell cycle arrest at the G1/S phase comparedto negative controls in blood cancer cells (i.e., REH leukemia cells)when the modified microRNAs are provided at a 50 nM concentration.

FIG. 10. Modified miR-15a expression reduces the ability of cancer stemcells to induce cancer cell colony formation. In colon cancer stemcells, expression of unmodified miR-15a (miR-15a) inhibited cancer cellcolony formation when compared to the ability of cancer stem cellsprovided with a non-specific control microRNA (Negative). Treatment withan exemplary modified miR-15a (5-FU-miR-15a) of the present disclosureprevented cancer cell colony formation completely.

FIG. 11. Other exemplary modified microRNAs exhibit efficacy as ananti-cancer agent in vivo. A colon cancer metastasis mouse model wasestablished via tail vein injection of metastatic human colon cancercells. Two weeks after establishing the metastasis, 40 of a modifiedmiR-15a nucleic acid composition as set forth in SEQ ID NO: 6 wasdelivered by intravenous injection with treatment frequency of oneinjection every other day for two weeks. The exemplary modified miR-15anucleic acid (mimic) was able to inhibit colon cancer metastasis whilenegative control miRNA (negative) had no effect. Mice treated withmodified miR-15a nucleic acid did not exhibit any toxicity.

FIGS. 12 A-12D. Exemplary modified miR-15a and miR-129 mimics of thepresent disclosure exhibit enhanced ability to inhibit human breastcancer (A549;C,D) and pancreatic cancer (Panc-1(A); AsPC-1(B)) cellproliferation compared to unmodified miR-15a (miR-15a) or unmodifiedmiR-129 (miR-129) or cells treated with negative controls.

FIGS. 13A-13B. Exemplary modified microRNAs of the present disclosureexhibit an enhanced ability to inhibit human colorectal cancer cellproliferation. Additional exemplary modified microRNAs were tested fortheir ability to inhibit colorectal cancer cell proliferation in HCT116human colorectal cancer cells. (A) An exemplary modified miR-140 mimicas set forth in SEQ ID NO: 9 was administered to human colorectal cancercells and revealed an increased ability to inhibit colorectal cancercell proliferation when compared to negative control microRNAs. (B) Anexemplary modified miR-192 mimic as set forth in SEQ ID NO: 11 wasadministered to human colorectal cancer cells and revealed an increasedability to inhibit colorectal cancer cell proliferation when compared tonegative control microRNAs.

FIGS. 14A-14E. All exemplary modified microRNAs of the presentdisclosure exhibit an enhanced ability to inhibit several types ofcancer. Cancer cell proliferation was inhibited by exogenous expressionof each of the following 5-FU-modified microRNA nucleic acids whencompared to negative controls (negative), miR-15a [SEQ ID NO: 6],miR-129 [SEQ ID NO: 4], miR-506 [SEQ ID NO: 15], miR-502 [SEQ ID NO:13], miR-34 [SEQ ID NO: 18], miR-200a [SEQ ID NO: 20], miR-200b [SEQ IDNO: 22], miR-200c [SEQ ID NO: 24], miR-145 [SEQ ID NO: 26], miR-194 [SEQID NO: 28], miR-let-7 [SEQ ID NO: 30], miR-215 [SEQ ID NO: 11] andmiR-140 [SEQ ID NO: 16] for each of cancer type tested. (A) Humanpancreatic cancer cell proliferation is inhibited by expression of eachmodified microRNA tested in Hs766T pancreatic cancer cells. (B) Gastriccancer cell proliferation is inhibited by expression of each modifiedmicroRNA tested in AGS stomach cancer cells. (C) Human breast cancercell proliferation is inhibited by expression of each modified microRNAtested in SKBR3 breast cancer cells. (D) Lung cancer cell proliferationis inhibited by expression of each modified microRNA tested in A549 lungcancer cells. (E) Leukemia cancer cell proliferation is inhibited byexpression of each modified microRNA as tested in an acute lymphocyticleukemia cell line (REH). Taken together, the data reveals that themodified microRNA compositions of the present disclosure display anincreased ability to inhibit all types of cancer cell proliferation whencompared to negative controls.

FIGS. 15A-15C. All exemplary modified microRNAs of the presentdisclosure exhibit displayed the ability to inhibit cancer cell growthin a dose dependent manner. Cancer cell proliferation was inhibited byexogenous expression of each of the following 5-FU-modified microRNAnucleic acids when compared to negative controls (negative), miR-15a[SEQ ID NO: 6], miR-129 [SEQ ID NO: 4], miR-506 [SEQ ID NO: 15], miR-502[SEQ ID NO: 13], miR-34 [SEQ ID NO: 18], miR-200a [SEQ ID NO: 20],miR-200b [SEQ ID NO: 22], miR-200c [SEQ ID NO: 24], miR-145 [SEQ ID NO:26], miR-194 [SEQ ID NO: 28], miR-let-7 [SEQ ID NO: 30], miR-215 [SEQ IDNO: 11] and miR-140 [SEQ ID NO: 16] for each of cancer type tested. (A,B) Human pancreatic cancer cell proliferation is inhibited in a dosedependent manner by each modified microRNA tested in two different humanpancreatic cancer cell lines (A, APSC-1; B, PANC-1). (C) Leukemia cancercell proliferation is inhibited in a dose dependent manner by eachmodified microRNA tested in an acute lymphocytic leukemia cell line(REH). Taken together, the data reveals that the modified microRNAcompositions of the present disclosure display an ability to inhibitmultiple types of cancer cell growth and proliferation in a dosedependent manner.

FIGS. 16A-16C. Another exemplary modified microRNA nucleic acid entercancer cells and effectively reduce target protein expression andinhibits tumor development and progression by inducing cell cyclearrest. (A) Graph showing target (ZEB-1 and Fibronectin) specificity andthe ability of an exemplary modified miR-200b (with all U bases replacedwith 5-FU, 5-FU-miR-200b) compared to that of control miRNA, and anunmodified miR-200b nucleic acid. (B) Modified miR-200b nucleic acids(5-FU-miR-200b) enter a breast cancer cell for triple negative breastcancer (MDA-MB-231 cell line) and breaks down TS-FdUMP indicating anticancer activity. (C) Expression of modified miR-200b (5-FU-miR-200b)significantly increases the G1/S ratio (top) and sub G1 population(bottom) of cells compared to expression of exogenous native miR-200band a negative control (miR-NC) indicating that modified miR-200binhibits breast cancer cell cycle progression.

FIGS. 17A-17B. Modified microRNA molecules can be delivered to cancercells without exogenous delivery vehicles. (A) MDA-MB-231 cells weretransfected with non-specific microRNA control nucleic acids (miR-NC),native miR-200b, or modified miR-200b (5-FU-miR-200b) in the presence ofoligofectamine or (B) contacted by NC (negative control), nativemiR-200b, or modified miR-200b (5-FU-miR-200b) without delivery vehicle(i.e., no oligofectamine). Modified miR-200b effectively reduced cellproliferation of breast cancer cells with or without delivery vehiclewhen compared to negative controls and native miR-200b. In contrast,exogenous miR-200b did not inhibit cell growth in the absence of adelivery vehicle.

FIGS. 18A-18B. Native miR-489 alone and in the presence of 5-FU showsthe ability to inhibit breast cancer cell proliferation to inhibitbreast cancer cell proliferation. (A) MDA-MB-231 breast cancer cellswere transfected with indicated native miR-489 nucleic acid compositions(miR-489) or negative control nucleic acid compositions (miR-NC) andincubated for 72 hours, followed by a 48 hour application of 5 μM 5-FU(5-FU+) or control substance (5-FU-). Results show breast cancer cellproliferation as measured by MTT assay. Column, mean from threeindependent experiments; bars, SD. *P<0.01; compared with the control.(B) Western blotting analysis p-Chk1, total Chk1 or actin from lysatesof MDA-MB-231, MDA-MB-468 and BT-549 TNBC cells transfected withnegative control (miR-NC) or native miR-489 nucleic acid compositions(miR-489) with or without treatment of 5 μM 5-FU for 48 hours.

FIGS. 19A-19B. Modified miR-489 nucleic acid compositions bind to aportion of the SUZ12 and MDC1 3′ untranslated region to inhibit SUZ12and MDC1 protein expression. (A) MDA-MB-231, HCC-1937 and BT-459 cellswere transfected with control miRNA (miR-NC) or native miR-489 (miR-489)nucleic acid compositions. Protein levels from cell lysates wereanalyzed by western blot with antibodies against MDC1 and SUZ12, showingthat native miR-489 inhibits MDC1 and SUZ12 protein expression in cancercells. GAPDH levels were used as loading control. Representative imageswere carried out at least three times. (B) Modified miR-489 having thenucleic acid set forth in SEQ ID NO: 32 retains the ability to bind to acomplementary portion the SUZ12 and MDC1 3′ untranslated region andinhibit SUZ12 and MDC1 protein expression in breast cancer cells, asshown by western blotting. Representative images were carried out atleast 3 times. All data are presented as the means±SD.

FIGS. 20A-20C. Modified miR-489 reduces breast cancer cell proliferation(A) MDA-MB-231 breast cancer cells were transfected with 50 nM controlmiRNA (miR-Ng), native miR-489 (miR-489) or a modified miR-489 (CMM489,SEQ ID NO: 32) nucleic acid composition. The rate of cancer cellproliferation was monitored by cell counting at days 1-6 andproliferation was measured by MTT assay. (B) MDA-MB-231 breast cancercells were transfected with 50 nM control miRNA (NC), native miR-489(miR-489) or a modified miR-489 (CMM489) nucleic acid composition,stained with propidium iodide and the percentage of cell population ineach cell cycle phase was analyzed by flow cytometry. (C) Expression ofmodified miR-489 (CMM489) significantly increases the G1/S ratio ofbreast cancer cells compared to expression of exogenous native miR-489(miR-489) and a negative control (NC) indicating that modified miR-489inhibits breast cancer cell cycle progression.

FIGS. 21A-21B. Delivery of a modified miR-489 nucleic acid compositiondoes not require the use of a transfection agent and modified miR-489retains target binding and inhibition. (A) MDA-MB-231 breast cancercells were transfected with a negative control microRNA (miR-NC), nativemiR-489 (miR-489) or an exemplary modified miR-489 (5-FU-miR-489, SEQ IDNO: 32) with or without oligofectamine transfection reagent and cellproliferation was measured by MTT assay. Modified miR-489 effectivelyreduced cell proliferation of breast cancer cells with or withoutdelivery vehicle when compared to negative controls and native miR-489.In contrast, exogenous miR-489 did not inhibit cell growth in theabsence of the oligofectamine transfection agent. (B) Whole cell lysatefrom MDA-MB-231 breast cancer cells transfected with: nothing(parental), negative control microRNA (miR-NC), native miR-489 (miR-489)or an exemplary modified miR-489 (CMM-489, SEQ ID NO: 32) without atransfection reagent (oligofectamine), and protein levels from celllysates were analyzed by western blot with antibodies against MDC1 andSUZ12 and TS-FdUMP, showing that the exemplary modified miR-489 nucleicacid composition maintains target binding and inhibits MDC1 and SUZ12protein expression in breast cancer cells. GAPDH was used as loadingcontrol.

FIG. 22. Modified miR-489 nucleic acid compositions significantlyreduced breast cancer growth and development in vivo in comparison tothe negative control microRNA and exogenous native miR-489. Inmetastatic mouse tumor models, breast cancer tumors were established viatail vein injection of MDA-MB-231 breast cancer cells. Mice were thentreated with negative control microRNA (miR-NC), native miR-489(miR-489) or an exemplary modified miR-489 (CMM-489, SEQ ID NO: 32) andtumor size was visualized.

DETAILED DESCRIPTION OF THE DISCLOSURE

The present disclosure provides nucleic acid compositions thatincorporate one or more halouracil molecules. Without being bound by anyone particular theory, surprisingly, the present disclosure reveals thatthe replacement of uracil nucleotides within a microRNA oligonucleotidesequence with a 5-halouracil increases the ability of the microRNA toinhibit cancer development, progression and tumorigenesis. Moreover, thedata herein shows that contacting a many types of cancer cells with amodified microRNA composition of the present disclosure regulatescell-cycle progression and reduces tumorigenesis by, for example,reducing cancer cell proliferation and increasing the efficacy ofchemotherapeutic agents. Furthermore, it is shown that the modifiedmicroRNAs of the present disclosure retain target specificity, can bedelivered without the use of harmful and ineffective delivery vehicles(e.g., nanoparticles), and exhibit enhanced potency and stabilitywithout abolishing the natural function of the endogenous microRNA. Assuch, the present disclosure provides various nucleic acid (e.g.,microRNA) compositions having 5-halouracil molecules incorporated intheir nucleic acid sequences and methods for using the same to treatcancer. The present disclosure further provides formulations, such aspharmaceutical compositions comprising the modified nucleic acidcompositions, and methods for treating cancers that includeadministration of the same to a subject in need thereof.

Nucleic Acid Compositions.

The term “microRNA” or “miRNA” or “miR” is used interchangeably to referto small non-coding ribose nucleic acid (RNA) molecules that are capableof regulating the expression of genes through interacting with messengerRNA molecules (mRNA), DNA or proteins. Typically, microRNAs are composedof nucleic acid sequences of about 19-25 nucleotides (bases) and arefound in mammalian cells. Mature microRNA molecules are single strandedRNA molecules processed from double stranded precursor transcripts thatform local hairpin structures. The hairpin structures are typicallycleaved by the Dicer enzyme to form a double stranded microRNA duplex.See, e.g., Bartel, Cell, (2004) 116 pp. 281-297. The term microRNA asused herein incorporates both the duplex (i.e., double stranded miRs)and single stranded miRs (i.e., mature miRs) in both the 5′ to 3′direction and complementary strand in the 3′ to 5′ direction. Inspecific embodiments, modified miRs of the present disclosure arecomposed of single stranded mature MiRs.

Usually, one of the two strands of a microRNA duplex is packaged in amicroRNA ribonucleoprotein complex (microRNP). A microRNP in, forexample, humans, also includes the proteins eIF2C2/Argonaute (Ago2), thehelicase Gemin3, and Gemin 4. Other members of the Argonaute proteinfamily, such as Ago1, 3, and 4, also associate with microRNAs and formmicroRNPs.

The term “modified microRNA”, “modified miRNA”, “modified miR” or“mimic” are used interchangeably herein to refer to a microRNA thatdiffers from the native or endogenous microRNA (unmodified microRNA)polynucleotide. More specifically, in the present disclosure a modifiedmicroRNA differs from the unaltered or unmodified microRNA nucleic acidsequence by one or more base. In some embodiments of the presentdisclosure, a modified microRNA of the present disclosure includes atleast one uracil (U) nucleotide base replaced by a 5-halouracil. Inother embodiments a modified microRNA includes an additional nucleotide(i.e., adenine (A), cytosine (C), uracil (U), and guanine (G)) and atleast one uracil base that is substituted with a 5-halouracil.

In one aspect of the present disclosure, nucleic acid compositions thatinclude a modified microRNA nucleotide sequence having at least oneuracil base (U, U bases) that has been replaced with a 5-halouracil,such as 5-fluorouracil (5-FU) are described. As further discussedherein, the nucleic acid compositions of the present disclosure areuseful, at least, in the treatment of all cancers. In particular, theexemplary modified microRNAs of the present disclosure have been shownherein to be effective in the treatment of colorectal cancer, pancreaticcancer, lung cancer, gastric cancer, blood cancers (e.g., leukemia) andbreast cancer.

In some embodiments, the nucleic acid compositions contain a nucleotidesequence that has been modified by derivatizing at least one of theuracil nucleobases at the 5-position with a group that provides asimilar effect as a halogen atom. In some embodiments, the groupproviding the similar effect has a similar size in weight or spatialdimension to a halogen atom, e.g., a molecular weight of up to or lessthan 20, 30, 40, 50, 60, 70, 80, 90, or 80 g/mol. In certainembodiments, the group providing a similar effect as a halogen atom maybe, for example, a methyl group, trihalomethyl (e.g., trifluoromethyl)group, pseudohalide (e.g., trifluoromethanesulfonate, cyano, or cyanate)or deuterium (D) atom. The group providing a similar effect as a halogenatom may be present in the absence of or in addition to a 5-halouracilbase in the microRNA nucleotide sequence.

Moreover, in other embodiments, the group providing a similar effect asa halogen atom may be located in the native (or seed) portion and/or inan appended portion of the microRNA nucleotide sequence, which will bereadily identified by one of ordinary skill in the art. In someembodiments, one or more (or all) of the above types of groups providinga similar effect as a halogen atom are excluded from the modified miRNAnucleotide sequence. When all such alternative groups are excluded, onlyone or more halogen atoms are present as substituents in the 5-positionof one or more uracil groups in the microRNA nucleotide sequence.

In certain embodiments, the modified microRNA has more than one, orexactly one uracil that has been replaced with a 5-halouracil.

In some embodiments, the modified microRNA nucleotide sequence includesthree, four, five, six, seven, eight or more uracil bases that have beenreplaced with a 5-halouracil.

In one embodiment, all of the uracil nucleotide bases of the modifiedmRNA have been replaced by a 5-halouracil.

In some embodiments, the 5-halouracil is, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil. In specific embodiments,the 5-halouracil is 5-fluorouracil.

The term “miR-129” as used herein, is meant to be synonymous with theterms “microRNA-129” or “miRNA-129” and refers to an oligonucleotidehaving the following nucleotide sequence: CUUUUUGCGGUCUGGGCUUGC [SEQ IDNO. 1], where it is understood that C=cytosine, U=uracil, and G=guaninebases. The foregoing nucleotide sequence is herein referred to as anunmodified miR-129 (i.e., “native”) sequence unless otherwise specified.In other embodiments, MiR-129 may also be referred to in the field ashsa-miR-129 with accession number MI0000252 for the stem loop containingdouble stranded microRNA; hsa-miR-129-5p for the mature miR 5′ to 3′strand as set forth in accession number MIMAT0000242; and hsa-miR-129-3pfor the 3′ to 5′ complementary strand of a duplex miR-129 molecule asset forth by accession number MIMAT0004548. MiR-129 is well known andhas been studied in detail. See, e.g., J. Wu et al., Cell Cycle, (2010)9:9, 1809-1818. As also well known in the art, the miR-129 sequence maybe modified to produce a “miR-129 mimic”, which has a sequence modifiedfrom the native sequence, but that retains the known function oractivity of the native miR-129. Unless otherwise stated, all suchmodified miR-129 compositions are herein considered to be within thescope of the term “miR-129 mimic” as used herein.

A particular modified miR-129 nucleic acid sequence (mimic) of interestcontains two U bases (i.e., two U-containing nucleotides) covalentlyappended to an end of the miR-129 native sequence, such as inCUUUUUGCGGUCUGGGCUUGC-UU [SEQ ID NO. 3]. In the foregoing sequence, thetwo terminal U bases continue or extend the miR-129 native sequence from21 nucleotide bases to 23 nucleotide bases. Generally, the miR-129 mimiccontains no more than one, two, three, four, or five additional bases(i.e., as additional nucleotides) covalently appended to the miR-129native sequence, wherein the additional bases are independently selectedfrom C, U, G, and C, or the additional bases may be exclusively U.Typically, the miR-129 is used in single-strand form, butdouble-stranded versions are also considered herein.

In one embodiment, the present disclosure is directed to nucleic acidcompositions that contain a miR-129 nucleotide sequence that has beenmodified by replacing at least one of the uracil nucleobases (i.e., Ubases) with a 5-halouracil, i.e., wherein at least one of the U bases inthe miR-129 sequence, whether in the native and/or in an appendedportion, is a 5-halouracil. The 5-halouracil can be, for example,5-fluorouracil, 5-chlorouracil, 5-bromouracil, or 5-iodouracil.

In a first set of embodiments, precisely one of the U bases in themiR-129 sequence is a 5-halouracil. In a second set of embodiments,precisely or at least two U bases in the miR-129 sequence are5-halouracils. In a third set of embodiments, precisely or at leastthree U bases in the miR-129 sequence are 5-halouracils. In a fourth setof embodiments, precisely or at least four U bases in the miR-129sequence are 5-halouracils. In a fifth set of embodiments, precisely orat least five U bases in the miR-129 sequence are 5-halouracils. In asixth set of embodiments, all of the U bases in the miR-129 sequence,whether in the native and/or in an appended portion, are 5-halouracils.

In a specific embodiment, the nucleic composition of the presentdisclosure has a modified microRNA nucleotide sequence ofCU^(F)U^(F)U^(F)U^(F)U^(F)GCGGU^(F)CU^(F)GGGCU^(F)U^(F)GC as set forthin SEQ ID NO. 4, wherein U^(F) is a halouracil, specifically5-fluorouracil.

The U bases that are replaced with 5-halouracils in the miR-129 sequencemay be located in an unmodified part of the miR-129 sequence, asprovided above, or, in the case of a miR-129 mimic, may be located inone or more U bases covalently appended to the native miR-129, as alsoprovided above. In other embodiments, a seed portion of the nativemiR-129 nucleotide sequence, GUUUUUGC remains unmodified with a5-halouracil while one or more (or all) of the remaining U bases in theremainder of the miR-129 nucleotide sequence are replaced with theequivalent number of 5-halouracils.

For example, in a specific embodiment, the nucleic acid composition ofthe present disclosure has a modified microRNA nucleotide sequence ofCUUUUUGCGGU^(F)CU^(F)GGGCU^(F)U^(F)GC as set forth in SEQ ID NO. 5,whereby U^(F) is a halouracil, specifically 5-fluorouracil.

In alternative embodiments, the nucleic acid composition contains amiR-129 nucleotide sequence that has been modified by derivatizing atleast one of the uracil (U) nucleobases at the 5-position with a groupthat provides a similar effect as a halogen atom. In some embodiments,the group providing the similar effect has a similar size in weight orspatial dimension to a halogen atom, e.g., a molecular weight of up toor less than 20, 30, 40, 50, 60, 70, 80, 90, or 80 g/mol. The groupproviding a similar effect as a halogen atom may be, for example, amethyl group, trihalomethyl (e.g., trifluoromethyl) group, pseudohalide(e.g., trifluoromethanesulfonate, cyano, or cyanate) or deuterium (D)atom. The group providing a similar effect as a halogen atom may bepresent in the absence of or in addition to a 5-halouracil base in themiR-129 nucleotide sequence. Moreover, the group providing a similareffect as a halogen atom may be located in the native (or seed) portionand/or in an appended portion of the miR-129 nucleotide sequence. Insome embodiments, one or more (or all) of the above types of groupsproviding a similar effect as a halogen atom are excluded from themiR-129 nucleotide sequence. When all such alternative groups areexcluded, only one or more halogen atoms are present as substituents inthe 5-position of one or more uracil groups in the miR-129 nucleotidesequence.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a miR-15a nucleotide sequencethat has been modified. In some embodiments, the miR-15a nucleotidesequence has been modified by replacing at least one of the U bases witha 5-halouracil.

The term “miR-15a”, as used herein, is meant to be synonymous with theterms “microRNA-15a” or “miRNA-15a” and refers to an oligonucleotidehaving the following nucleotide sequence: UAGCAGCACAUAAUGGUUUGUG [SEQ IDNO. 2], where it is understood that A=adenine, C=cytosine, U=uracil, andG=guanine bases. The foregoing nucleotide sequence is herein referred toas a miR-15a unmodified (i.e., “native”) sequence unless otherwisespecified. In other embodiments, MiR-15a may also be referred to in thefield as hsa-miR-15a with accession number(s) MI0000069 for the stemloop containing double stranded microRNA; and hsa-miR-15a-5p withaccession number MI0000068 for the mature miR 5′ to 3′; andhsa-miR-15a-3p for the 3′ to 5′ complementary strand of a duplex miR-15amolecule as set forth by accession number MIMAT0004488. MiR-15a is wellknown and has been studied in detail, e.g., Xie T, et al. Clin TranslOncol. (2015) 17(7):504-10; and Acunzo M, and Croce C M, Clin. Chem.(2016) 62(4):655-6. As stated above for miR-129 mimics, methods forcreating a miR-15a mimic are known by those of ordinary skill in theart. Unless otherwise stated, all such modified miR-15a forms are hereinconsidered to be within the scope of the term “miR-15a mimic”, as usedherein.

Generally, a modified miR-15a (i.e., miR-15a mimic) contains no morethan one, two, three, four, or five additional nucleotides covalentlyappended to the miR-15a native sequence, wherein the additional basesare independently selected from C, U, G, and C, or the additional basesmay be exclusively U. Typically, the miR-15a is used in single-strandform, but double-stranded versions are also considered herein.

In some embodiments, at least one of the U bases in the miR-15asequence, whether in the native and/or in an appended portion, is a5-halouracil. The 5-halouracil can be, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil.

In a one set of embodiments, precisely one of the U bases in the miR-15asequence is a 5-halouracil. In a second set of embodiments, precisely orat least two U bases in the miR-15a sequence are 5-halouracils. Inanother set of embodiments, precisely or at least three U bases in themiR-15a oligonucleotide sequence are 5-halouracils. In otherembodiments, precisely or at least four U bases in the miR-15a sequenceare 5-halouracils. In some embodiments, precisely or at least five Ubases in the miR-15a sequence are 5-halouracils. In a yet otherembodiments, precisely or at least six U bases in the miR-15a sequenceare 5-halouracils. In specific embodiments, all of the U bases in themiR-15a sequence, whether in the native and/or in an appended portion,are 5-halouracils.

In one embodiment, the nucleic acid composition of the presentdisclosure has a modified microRNA nucleotide sequence ofU^(F)AGCAGCACAU^(F)AAU^(F)GGU^(F)U^(F)U^(F)GU^(F)G [SEQ ID NO. 6],wherein U^(F) is a halouracil, specifically 5-fluorouracil.

The U bases that are replaced with 5-halouracils in the miR-15a sequencemay be located in an unmodified part of the miR-15a sequence, asprovided above, or, in the case of a miR-15a mimic, may be located inone or more uracil bases that are appended to the native miR-15a, asalso provided above.

In other embodiments, a seed portion of the native miR-15a nucleotidesequence, UAGCAGCA, remains unmodified with a 5-halouracil while one ormore (or all) of the remaining U bases in the remainder of the miR-15anucleotide sequence (non-seed portion) are replaced with a 5-halouracil.

In specific embodiments, the nucleic acid composition of the presentdisclosure has a modified miR-15a nucleotide sequence ofUAGCAGCACAU^(F)AAU^(F)GGU^(F)U^(F)U^(F)GU^(F)G [SEQ ID NO. 7], whereinU^(F) is a halouracil, specifically 5-fluorouracil.

In certain embodiments, the nucleic acid composition contains a miR-15anucleotide sequence that has been modified by derivatizing at least oneof the uracil (U) nucleobases at the 5-position with a group thatprovides a similar effect as a halogen atom. In some embodiments, thegroup providing the similar effect has a similar size in weight orspatial dimension to a halogen atom, e.g., a molecular weight of up toor less than 20, 30, 40, 50, 60, 70, 80, 90, or 80 g/mol. The groupproviding a similar effect as a halogen atom may be, for example, amethyl group, trihalomethyl (e.g., trifluoromethyl) group, pseudohalide(e.g., trifluoromethanesulfonate, cyano, or cyanate) or deuterium (D)atom. The group providing a similar effect as a halogen atom may bepresent in the absence of or in addition to a 5-halouracil base in themiR-15a nucleotide sequence. Moreover, the group providing a similareffect as a halogen atom may be located in the native (or seed) portionand/or in an appended portion of the miR-15a nucleotide sequence.

In some embodiments, one or more (or all) of the above types of groupsproviding a similar effect as a halogen atom are excluded from miR-15anucleotide sequence. When all such alternative groups are excluded, onlyone or more halogen atoms are present as substituents in the 5-positionof one or more uracil groups in the miR-15a nucleotide sequence.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a miR-140 nucleotide sequencethat has been modified. In some embodiments, the miR-140 nucleotidesequence has been modified by replacing at least one of the U bases witha 5-halouracil.

The term “miR-140”, as used herein, is meant to be synonymous with theterms “microRNA-140” or “miRNA-140” and refers to an oligonucleotidehaving the following nucleotide sequence: CAGUGGUUUUACCCUAUGGUAG [SEQ IDNO. 8], where it is understood that A=adenine, C=cytosine, U=uracil, andG=guanine bases. The foregoing nucleotide sequence is herein referred toas a miR-140 unmodified (i.e., “native”) sequence unless otherwisespecified. In other embodiments, MiR-140 may also be referred ashsa-miR-140 with accession number MI0000456 for the stem loop containingdouble stranded microRNA; hsa-miR-140-5p for the mature miR 5′ to 3′strand as set forth in accession number MIMAT0000431 or NT_010498; andhsa-miR-140-3p for the 3′ to 5′ complementary strand of a duplex miR-140molecule as set forth by accession number MIMAT0004597. MiR-140 is wellknown and has been studied in detail, e.g., Zhai, H. et al., Oncotarget.(2015) 6: 19735-46. As stated above for exemplary mimics miR-129 andmiR-15a, methods for creating a miR-140 mimic are known by those ofordinary skill in the art. Unless otherwise stated, all such modifiedmiR-140 forms are herein considered to be within the scope of the term“miR-140 mimic”, as used herein.

Generally, a modified miR-140 nucleic acid (i.e., miR-140 mimic)contains no more than one, two, three, four, or five additionalnucleotides covalently appended to the miR-140 native sequence, whereinthe additional bases are independently selected from C, U, G, and C, orthe additional bases may be exclusively U. Typically, the miR-140 mimicis used in single-strand form, but double-stranded versions are alsoconsidered herein.

In some embodiments, at least one of the U bases in the miR-140sequence, whether in the native and/or in an appended portion, is a5-halouracil. The 5-halouracil can be, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil.

In one set of embodiments, precisely one of the U bases in the miR-140mimic sequence is a 5-halouracil. In a second set of embodiments,precisely or at least two U bases in the miR-140 sequence are5-halouracils. In another set of embodiments, precisely or at leastthree U bases in the miR-140 oligonucleotide sequence are 5-halouracils.In other embodiments, precisely or at least four U bases in the miR-140sequence are 5-halouracils. In some embodiments, precisely or at leastfive U bases in the miR-140 mimic sequence are 5-halouracils. In a yetother embodiments, precisely or at least six U bases in the miR-140mimic sequence are 5-halouracils. In specific embodiments, all of the Ubases in the miR-140 sequence, whether in the native and/or in anappended portion, are 5-halouracils.

In an exemplary embodiment, the nucleic acid composition of the presentdisclosure has a modified miR-140 nucleotide sequence ofCAGU^(F)GGUUUUACCCU^(F)AUGGU^(F)AG [SEQ ID NO. 9], wherein U^(F) is ahalouracil, specifically 5-fluorouracil.

In another embodiment, the nucleic acid composition of the presentdisclosure has a modified miR-140 nucleotide sequence ofUAGCAGCACAU^(F)AAU^(F)GGU^(F)U^(F)U^(F)GU^(F)G [SEQ ID NO. 16], whereinU^(F) is a halouracil, specifically 5-fluorouracil.

The U bases that are replaced with 5-halouracils in a miR-140 mimicsequence may be located in an unmodified part of the miR-140 sequence,as provided above, or may be located in one or more uracil bases thatare appended to the native miR-140 sequence, as provided above.

In other embodiments, a seed portion of the native miR-140 nucleotidesequence, remains unmodified with a 5-halouracil while one or more (orall) of the remaining U bases in the remainder of the miR-140 nucleotidesequence (non-seed portion) are replaced with a 5-halouracil.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a miR-192 nucleotide sequencethat has been modified. In some embodiments, the miR-192 nucleotidesequence has been modified by replacing at least one of the U bases witha 5-halouracil.

The term “miR-192”, as used herein, is meant to be synonymous with theterms “microRNA-192”, “miRNA-192” “microRNA-215”, “miR-215” or“miRNA-215” and refers to an oligonucleotide having the followingnucleotide sequence: CUGACCUAUGAAUUGACAGCC [SEQ ID NO. 10], where it isunderstood that A=adenine, C=cytosine, U=uracil, and G=guanine bases.The foregoing nucleotide sequence is herein referred to as a miR-192unmodified (i.e., “native”) sequence unless otherwise specified. In someembodiments, miR-192 may be referred to in the field as hsa-miR-192 orhsa-miR-215 with accession numbers MI0000234, or MI0000291 for the stemloop containing double stranded microRNA; hsa-miR-192-5p orhsa-miR-215-5p for the mature miR 5′ to 3′ strand as set forth inaccession number MIMAT0000222 and MIMAT0000272, respectively; andhsa-miR-192-3p or hsa-miR-215-3p for the 3′ to 5′ complementary strandof a duplex molecule as set forth by accession number MIMAT0004543 andMIMAT0026476, respectively. MiR-192 is well known and has been studiedin detail, e.g., Song, B. et al., Clin. Cancer Res. (2008), 14:8080-8086, and Song, B. et al., Mol. Cancer. (2010), 9:96 pp. 1476-4598.As stated above for exemplary mimics miR-129, miR-140 and miR-15a,methods for creating a miR-192 mimics are known by those of ordinaryskill in the art. Unless otherwise stated, all such modified miR-192nucleic acid forms are herein considered to be within the scope of theterm “miR-192 mimic”, as used herein.

Generally, a modified miR-192 (i.e., miR-192 mimic) contains no morethan one, two, three, four, or five additional nucleotides covalentlyappended to the miR-192 native sequence, wherein the additional basesare independently selected from C, U, G, and C, or the additional basesmay be exclusively U. Typically, the miR-192 mimic is used insingle-strand form, but double-stranded versions are also consideredherein.

In some embodiments, at least one of the U bases in the miR-192 ormiR-215 sequence, whether in the native and/or in an appended portion,is a 5-halouracil. The 5-halouracil can be, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil.

In another set of embodiments, precisely one of the U bases in themiR-192 mimic sequence is a 5-halouracil. In a second set ofembodiments, precisely or at least two U bases in the miR-192 sequenceare 5-halouracils. In another set of embodiments, precisely or at leastthree U bases in the miR-192 oligonucleotide sequence are 5-halouracils.In other embodiments, precisely or at least four U bases in the miR-192sequence are 5-halouracils. In specific embodiments, all of the U basesin the miR-192 sequence, whether in the native and/or in an appendedportion, are 5-halouracils.

In an exemplary embodiment, the nucleic acid composition of the presentdisclosure has a modified miR-192 nucleotide sequence ofCU^(F)GACCU^(F)AU^(F)GAAU^(F)U^(F)GACAGCC [SEQ ID NO. 11], wherein U^(F)is a halouracil, specifically 5-fluorouracil.

The U bases that are replaced with 5-halouracils in the miR-192 mimicsequence may be located in an unmodified part of the miR-192 sequence,as provided above, or may be located in one or more uracil bases thatare appended to the native miR-192 sequence, as provided above.

In other embodiments, a seed portion of the native miR-192 nucleotidesequence remains unmodified with a 5-halouracil while one or more (orall) of the remaining U bases in the remainder of the miR-192 nucleotidesequence (non-seed portion) are replaced with a 5-halouracil orcombination thereof.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a miR-502 nucleotide sequencethat has been modified. In some embodiments, the miR-502 nucleotidesequence has been modified by replacing at least one of the U bases witha 5-halouracil.

The term “miR-502”, as used herein, is meant to be synonymous with theterms “microRNA-502” or “miRNA-502” and refers to an oligonucleotidehaving the following nucleotide sequence: AUCCUUGCUAUCUGGGUGCUA [SEQ IDNO. 12], where it is understood that A=adenine, C=cytosine, U=uracil,and G=guanine bases. The foregoing nucleotide sequence is hereinreferred to as a miR-502 unmodified (i.e., “native”) sequence unlessotherwise specified. In other embodiments, MiR-502 may also be referredto in the field as hsa-miR-502 with accession number MI0003186 for thestem loop containing double stranded microRNA; hsa-miR-502-5p for themature miR 5′ to 3′ strand as set forth in accession numberMIMAT0002873; and hsa-miR-502-3p for the 3′ to 5′ complementary strandof a duplex miR-502 molecule as set forth by accession numberMIMAT0004775. MiR-502 is well known and has been studied in detail,e.g., Zhai, H, et al., Oncogene. (2013), 32:12 pp. 1570-1579. As statedabove for exemplary mimics miR-129, miR-140, miR-192 and miR-15a,methods for creating a miR-502 mimics are known by those of ordinaryskill in the art. Unless otherwise stated, all such modified miR-502nucleic acid forms are herein considered to be within the scope of theterm “miR-502 mimic”, as used herein.

Generally, a modified miR-502 (i.e., miR-502 mimic) contains no morethan one, two, three, four, or five additional nucleotides covalentlyappended to the miR-502 native sequence, wherein the additional basesare independently selected from C, U, G, and C, or the additional basesmay be exclusively U. Typically, the miR-502 mimic is used insingle-strand form, but double-stranded versions are also consideredherein.

In some embodiments, at least one of the U bases in the miR-502sequence, whether in the native and/or in an appended portion, is a5-halouracil. The 5-halouracil can be, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil.

In another set of embodiments, precisely one of the U bases in themiR-502 mimic sequence is a 5-halouracil. In a second set ofembodiments, precisely or at least two U bases in the miR-502 sequenceare 5-halouracils. In another set of embodiments, precisely or at leastthree U bases in the miR-502 oligonucleotide sequence are 5-halouracils.In other embodiments, precisely or at least four U bases in the miR-502sequence are 5-halouracils. In other embodiments, precisely or at leastfive U bases in the miR-502 sequence are 5-halouracils. In otherembodiments, precisely or at least six U bases in the miR-502 sequenceare 5-halouracils. In other embodiments, precisely or at least seven Ubases in the miR-502 sequence are 5-halouracils. In specificembodiments, all of the U bases in the miR-502 sequence, whether in thenative and/or in an appended portion, are 5-halouracils.

In an exemplary embodiment, the nucleic acid composition of the presentdisclosure has a modified miR-502 nucleotide sequence ofAU^(F)CCU^(F)U^(F)GCUAU^(F)CU^(F)GGGU^(F)GCU^(F)A [SEQ ID NO. 13],wherein U^(F) is a halouracil, specifically 5-fluorouracil.

The U bases that are replaced by 5-halouracils in the miR-502 mimicsequence may be located in an unmodified part of the miR-502 sequence,as provided above, or may be located in one or more uracil bases thatare appended to the native miR-502 sequence, as provided above.

In other embodiments, a seed portion of the native miR-502 nucleotidesequence remains unmodified with a 5-halouracil while one or more (orall) of the remaining U bases in the remainder of the miR-502 nucleotidesequence (non-seed portion) are replaced by a 5-halouracil orcombination thereof.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a miR-506 nucleotide sequencethat has been modified. In some embodiments, the miR-506 nucleotidesequence has been modified by replacing at least one of the U bases witha 5-halouracil.

The term “miR-506”, as used herein, is meant to be synonymous with theterms “microRNA-506” or “miRNA-506” and refers to an oligonucleotidehaving the following nucleotide sequence: UAUUCAGGAAGGUGUUACUUAA [SEQ IDNO. 14], where it is understood that A=adenine, C=cytosine, U=uracil,and G=guanine bases. The foregoing nucleotide sequence is hereinreferred to as a miR-506 unmodified (i.e., “native”) sequence unlessotherwise specified. In other embodiments, miR-506 may also be referredto in the field as hsa-miR-506 with accession number MI0003193 for thestem loop containing double stranded microRNA; hsa-miR-506-5p for themature miR 5′ to 3′ strand as set forth in accession numberMIMAT0022701; and hsa-miR-506-3p for the 3′ to 5′ complementary strandof a duplex miR-506 molecule as set forth by accession numberMIMAT0002878. MiR-506 is well known and has been studied in detail,e.g., Li, J, et al., Oncotarget. (2016), 7:38 pp. 62778-62788, and Li,J. et al., Oncogene. (2016) 35 pp. 5501-5514. As stated above forexemplary mimics miR-129, miR-140, miR-502, miR-192 and miR-15a, methodsfor creating a miR-506 mimics are known by those of ordinary skill inthe art. Unless otherwise stated, all such modified miR-506 nucleic acidforms are herein considered to be within the scope of the term “miR-506mimic”, as used herein.

Generally, a modified miR-506 (i.e., miR-506 mimic) contains no morethan one, two, three, four, or five additional nucleotides covalentlyappended to the miR-506 native sequence, wherein the additional basesare independently selected from C, U, G, and C, or the additional basesmay be exclusively U. Typically, the miR-506 mimic is used insingle-strand form, but double-stranded versions are also consideredherein.

In some embodiments, at least one of the U bases in the miR-506sequence, whether in the native and/or in an appended portion, is a5-halouracil. The 5-halouracil can be, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil.

In another set of embodiments, precisely one of the U bases in themiR-506 mimic sequence is a 5-halouracil. In a second set ofembodiments, precisely or at least two U bases in the miR-506 sequenceare 5-halouracils. In another set of embodiments, precisely or at leastthree U bases in the miR-506 oligonucleotide sequence are 5-halouracils.In other embodiments, precisely or at least four U bases in the miR-506sequence are 5-halouracils. In other embodiments, precisely or at leastfive U bases in the miR-506 sequence are 5-halouracils. In otherembodiments, precisely or at least six U bases in the miR-506 sequenceare 5-halouracils. In other embodiments, precisely or at least seven Ubases in the miR-506 sequence are 5-halouracils. In specificembodiments, all of the U bases in the miR-506 sequence, whether in thenative and/or in an appended portion, are 5-halouracils.

In an exemplary embodiment, the nucleic acid composition of the presentdisclosure has a modified miR-506 nucleotide sequence ofU^(F)AU^(F)U^(F)CAGGAAGGU^(F)GU^(F)U^(F)ACU^(F)U^(F)AA [SEQ ID NO. 15],wherein U^(F) is a halouracil, specifically 5-fluorouracil.

The U bases that are replaced with 5-halouracils in the miR-506 mimicsequence may be located in an unmodified part of the miR-506 sequence,as provided above, or may be located in one or more uracil bases thatare appended to the native miR-506 sequence, as provided above.

In other embodiments, a seed portion of the native miR-506 nucleotidesequence remains unmodified with a 5-halouracil while one or more (orall) of the remaining U bases in the remainder of the miR-506 nucleotidesequence (non-seed portion) are replaced with a 5-halouracil orcombination thereof.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a miR-34 nucleotide sequence thathas been modified. In some embodiments, the miR-34 nucleotide sequencehas been modified by replacing at least one of the U bases with a5-halouracil.

The term “miR-34”, as used herein, is meant to be synonymous with theterms “microRNA-34”, “miR-34a” or “miRNA-34” and refers to anoligonucleotide having the following nucleotide sequence:UGGCAGUGUCUUAGCUGGUUGU [SEQ ID NO. 17]. The foregoing nucleotidesequence is herein referred to as the miR-34 unmodified (i.e., “native”)sequence unless otherwise specified. In other embodiments, miR-34 mayalso be referred to in the field as hsa-miR-34 with accession numberMI0000268 for the stem loop containing double stranded microRNA;hsa-miR-34a-5p for the mature miR 5′ to 3′ strand as set forth inaccession number MIMAT0000255; and hsa-miR-34a-3p for the 3′ to 5′complementary strand of a duplex miR-129 molecule as set forth byaccession number MIMAT0004557. MiR-34 is well known and has been studiedin detail. See, e.g., Lui, W O, et al., Cancer Res. 67 pp. 6031-6043(2007). As stated above for exemplary mimics miR-129, miR-140, miR-502,miR-506 miR-192 and miR-15a, methods for creating a modified miR-34polynucleotides are known by those of ordinary skill in the art. Unlessotherwise stated, all such modified miR-34 nucleic acid forms are hereinconsidered to be within the scope of the term “miR-34 mimic” or“modified miR-34”, as used herein.

Generally, a modified miR-34 (i.e., miR-34 mimic) contains no more thanone, two, three, four, or five additional nucleotides covalentlyappended to the miR-34 native sequence, wherein the additional bases areindependently selected from C, U, G, and C, or the additional bases maybe exclusively U. Typically, the miR-34 mimic is used in single-strandform, but double-stranded versions are also considered herein.

In some embodiments, at least one of the U bases in the miR-34 sequence,whether in the native and/or in an appended portion, is a 5-halouracil.The 5-halouracil can be, for example, 5-fluorouracil, 5-chlorouracil,5-bromouracil, or 5-iodouracil.

In other embodiments, precisely one of the U bases in the miR-34 mimicsequence is a 5-halouracil. In a second set of embodiments, precisely orat least two U bases in the miR-34 sequence are 5-halouracils. Inanother set of embodiments, precisely or at least three U bases in themiR-34 oligonucleotide sequence are 5-halouracils. In other embodiments,precisely or at least four U bases in the miR-34 sequence are5-halouracils. In other embodiments, precisely or at least five U basesin the miR-34 sequence are 5-halouracils. In other embodiments,precisely or at least six U bases in the miR-34 sequence are5-halouracils. In other embodiments, precisely or at least seven U basesin the miR-34 sequence are 5-halouracils. In yet other embodiments,precisely or at least eight U bases in the miR-34 sequence are5-halouracils. In specific embodiments, all of the U bases in the miR-34sequence, whether in the native and/or in an appended portion, are5-halouracils.

In an exemplary embodiment, the nucleic acid composition of the presentdisclosure has a modified miR-34 nucleotide sequence ofU^(F)GGCAGU^(F)GU^(F)CU^(F)U^(F)AGCU^(F)GGU^(F)U^(F)GU^(F) [SEQ ID NO.18], wherein U^(F) is a halouracil, specifically 5-fluorouracil.

The U bases that are replaced with 5-halouracils in the modified miR-34sequence may be located in an unmodified part of the miR-34 sequence, asprovided above, or may be located in one or more uracil bases that areappended to the native miR-34 sequence, as provided above.

In other embodiments, a seed portion of the native miR-34 nucleotidesequence remains unmodified with a 5-halouracil while one or more (orall) of the remaining U bases in the remainder of the miR-34 nucleotidesequence (non-seed portion) are replaced with a 5-halouracil orcombination thereof.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a miR-200a nucleotide sequencethat has been modified. In some embodiments, the miR-200a nucleotidesequence has been modified by replacing at least one of the U bases witha 5-halouracil.

The term “miR-200a”, as used herein, is meant to be synonymous with theterms “microRNA-200a” or “miRNA-200a” and refers to an oligonucleotidehaving the following nucleotide sequence: UAACACUGUCUGGUAACGAUGU [SEQ IDNO. 19]. The foregoing nucleotide sequence is herein referred to as themiR-200a unmodified (i.e., “native”) sequence unless otherwisespecified. In other embodiments, MiR-200a may also be referred to in thefield as hsa-miR-200a with accession number MI0000737 for the stem loopcontaining double stranded microRNA; hsa-miR-200a-5p for the mature miR5′ to 3′ strand as set forth in accession number MIMAT0001620; andhsa-miR-200a-3p for the 3′ to 5′ complementary strand of a duplexmiR-200a molecule as set forth by accession number MIMAT000682. MiR-200ais well known and has been studied in detail. See, e.g., Lagos-QuintanaM, et al., RNA. 9: pp. 175-179 (2003). As stated above, methods forcreating modified miR-200a polynucleotides are known by those ofordinary skill in the art. Unless otherwise stated, all such modifiedmiR-200a nucleic acid forms are herein considered to be within the scopeof the term “miR-200a mimic” or “modified miR-200a”, as used herein.

Generally, a modified miR-200a (i.e., miR-200a mimic) contains no morethan one, two, three, four, or five additional nucleotides covalentlyappended to the miR-200a native sequence, wherein the additional basesare independently selected from C, U, G, and C, or the additional basesmay be exclusively U. Typically, the miR-200a mimic is used insingle-strand form, but double-stranded versions are also consideredherein.

In some embodiments, at least one of the U bases in the miR-200asequence, whether in the native and/or in an appended portion, is a5-halouracil. The 5-halouracil can be, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil.

In other embodiments, precisely one of the U bases in the miR-200a mimicsequence is a 5-halouracil. In a second set of embodiments, precisely orat least two U bases in the miR-200a sequence are 5-halouracils. Inanother set of embodiments, precisely or at least three U bases in themiR-200a oligonucleotide sequence are 5-halouracils. In otherembodiments, precisely or at least four U bases in the miR-200a sequenceare 5-halouracils. In other embodiments, precisely or at least five Ubases in the miR-200a sequence are 5-halouracils. In other embodiments,precisely or at least six U bases in the miR-200a sequence are5-halouracils. In a specific embodiment, all of the U bases in themiR-200a sequence, whether in the native and/or in an appended portion,are 5-halouracils.

In an exemplary embodiment, the nucleic acid composition of the presentdisclosure has a modified miR-200a nucleotide sequence ofU^(F)AACACU^(F)GU^(F)CU^(F)GGU^(F)AACGAU^(F)GU^(F) [SEQ ID NO. 20],wherein U^(F) is a halouracil, specifically 5-fluorouracil.

The U bases that are replaced with 5-halouracils in the modifiedmiR-200a sequence may be located in an unmodified part of the miR-200asequence, as provided above, or may be located in one or more uracilbases that are appended to the native miR-200a sequence, as providedabove.

In other embodiments, a seed portion of the native miR-200a nucleotidesequence remains unmodified with a 5-halouracil while one or more (orall) of the remaining U bases in the remainder of the miR-200anucleotide sequence (non-seed portion) are replaced with a 5-halouracilor combination thereof.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a miR-200b nucleotide sequencethat has been modified. In some embodiments, the miR-200b nucleotidesequence has been modified by replacing at least one of the U bases witha 5-halouracil.

The term “miR-200b”, as used herein, is meant to be synonymous with theterms “microRNA-200b” or “miRNA-200b” and refers to an oligonucleotidehaving the following nucleotide sequence: UAAUACUGCCUGGUAAUGAUGA [SEQ IDNO. 21]. The foregoing nucleotide sequence is herein referred to as themiR-200b unmodified (i.e., “native”) sequence unless otherwisespecified. In other embodiments, miR-200b may also be referred to in thefield as hsa-miR-200b with accession number MI0000342 for the stem loopcontaining double stranded microRNA; hsa-miR-200b-5p for the mature miR5′ to 3′ strand as set forth in accession number MIMAT00004571; andhsa-miR-200b-3p for the 3′ to 5′ complementary strand of a duplexmiR-200b molecule as set forth by accession number MIMAT0000318.MiR-200b is well known and has been studied in detail. See, e.g.,Altuvia Y, et al., Nucleic Acids Res. 33 pp. 2697-2706 (2005). As above,methods for creating modified miR-200b polynucleotides are known bythose of ordinary skill in the art. Unless otherwise stated, all suchmodified miR-200b nucleic acid forms are herein considered to be withinthe scope of the term “miR-200b mimic” or “modified miR-200b”, as usedherein.

Generally, a modified miR-200b (i.e., miR-200b mimic) contains no morethan one, two, three, four, or five additional nucleotides covalentlyappended to the miR-200b native sequence, wherein the additional basesare independently selected from C, U, G, and C, or the additional basesmay be exclusively U. Typically, the miR-200b mimic is used insingle-strand form, but double-stranded versions are also consideredherein.

In some embodiments, at least one of the U bases in the miR-200bsequence, whether in the native and/or in an appended portion, is a5-halouracil. The 5-halouracil can be, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil.

In other embodiments, precisely one of the U bases in the miR-200b mimicsequence is a 5-halouracil. In a second set of embodiments, precisely orat least two U bases in the miR-200b sequence are 5-halouracils. Inanother set of embodiments, precisely or at least three U bases in themiR-200b oligonucleotide sequence are 5-halouracils. In otherembodiments, precisely or at least four U bases in the miR-200b sequenceare 5-halouracils. In other embodiments, precisely or at least five Ubases in the miR-200b sequence are 5-halouracils. In other embodiments,precisely or at least six U bases in the miR-200b sequence are5-halouracils. In a specific embodiment, all of the U bases in themiR-200b sequence, whether in the native and/or in an appended portion,are 5-halouracils.

In an exemplary embodiment, the nucleic acid composition of the presentdisclosure has a modified miR-200b nucleotide sequence ofU^(F)AAU^(F)ACU^(F)GCCU^(F)GGU^(F)AAU^(F)GAU^(F)GA [SEQ ID NO. 22],wherein U^(F) is a halouracil, specifically 5-fluorouracil.

The U bases that are replaced with 5-halouracils in the modifiedmiR-200b sequence may be located in an unmodified part of the miR-200bsequence, as provided above, or may be located in one or more uracilbases that are appended to the native miR-200b sequence, as providedabove.

In other embodiments, a seed portion of the native miR-200b nucleotidesequence remains unmodified with a 5-halouracil while one or more (orall) of the remaining U bases in the remainder of the miR-200bnucleotide sequence (non-seed portion) are replaced with a 5-halouracilor combination thereof.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a miR-200c nucleotide sequencethat has been modified. In some embodiments, the miR-200c nucleotidesequence has been modified by replacing at least one of the U bases witha 5-halouracil.

The term “miR-200c”, as used herein, is meant to be synonymous with theterms “microRNA-200c” or “miRNA-200c” and refers to an oligonucleotidehaving the following nucleotide sequence: UAAUACUGCCGGGUAAUGAUGGA [SEQID NO. 23]. The foregoing nucleotide sequence is herein referred to asthe miR-200c unmodified (i.e., “native”) sequence unless otherwisespecified. In other embodiments, miR-200c may also be referred to in thefield as hsa-miR-200c with accession number MI0000650 for the stem loopcontaining double stranded microRNA; hsa-miR-200c-5p for the mature miR5′ to 3′ strand as set forth in accession number MIMAT00004657; andhsa-miR-200c-3p for the 3′ to 5′ complementary strand of a duplexmiR-200c molecule as set forth by accession number MIMAT0000617.MiR-200c is well known and has been studied in detail. See, e.g.,Landgraf P, et al., Cell. 129 pp. 1401-1414 (2007). As stated above,methods for creating modified miR-200c polynucleotides are known bythose of ordinary skill in the art. Unless otherwise stated, all suchmodified miR-200c nucleic acid forms are herein considered to be withinthe scope of the term “miR-200c mimic” or “modified miR-200c”, as usedherein.

Generally, a modified miR-200c (i.e., miR-200c mimic) contains no morethan one, two, three, four, or five additional nucleotides covalentlyappended to the miR-200c native sequence, wherein the additional basesare independently selected from C, U, G, and C, or the additional basesmay be exclusively U. Typically, the miR-200c mimic is used insingle-strand form, but double-stranded versions are also consideredherein.

In some embodiments, at least one of the U bases in the miR-200csequence, whether in the native and/or in an appended portion, is a5-halouracil. The 5-halouracil can be, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil.

In other embodiments, precisely one of the U bases in the miR-200c mimicsequence is a 5-halouracil. In a second set of embodiments, precisely orat least two U bases in the miR-200c sequence are 5-halouracils. Inanother set of embodiments, precisely or at least three U bases in themiR-200c oligonucleotide sequence are 5-halouracils. In otherembodiments, precisely or at least four U bases in the miR-200c sequenceare 5-halouracils. In other embodiments, precisely or at least five Ubases in the miR-200c sequence are 5-halouracils. In a specificembodiment, all of the U bases in the miR-200c sequence, whether in thenative and/or in an appended portion, are 5-halouracils.

In an exemplary embodiment, the nucleic acid composition of the presentdisclosure has a modified miR-200c nucleotide sequence ofU^(F)AAU^(F)ACU^(F)GCCGGGU^(F)AAU^(F)GAU^(F)GGA [SEQ ID NO. 24], whereinU^(F) is a halouracil, specifically 5-fluorouracil.

The U bases that are replaced with 5-halouracils in the modifiedmiR-200c sequence may be located in an unmodified part of the miR-200csequence, as provided above, or may be located in one or more uracilbases that are appended to the native miR-200c sequence, as providedabove.

In other embodiments, a seed portion of the native miR-200c nucleotidesequence remains unmodified with a 5-halouracil while one or more (orall) of the remaining U bases in the remainder of the miR-200cnucleotide sequence (non-seed portion) are replaced with a 5-halouracilor combination thereof.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a miR-145 nucleotide sequencethat has been modified. In some embodiments, the miR-145 nucleotidesequence has been modified by replacing at least one of the U bases witha 5-halouracil.

The term “miR-145”, as used herein, is meant to be synonymous with theterms “microRNA-145” or “miRNA-145” and refers to an oligonucleotidehaving the following nucleotide sequence: GUCCAGUUUUCCCAGGAAUCCCU [SEQID NO. 25], where it is understood that A=adenine, C=cytosine, U=uracil,and G=guanine bases. The foregoing nucleotide sequence is hereinreferred to as a miR-145 unmodified (i.e., “native”) sequence unlessotherwise specified. In some embodiments, miR-145 may be referred to inas hsa-miR-145 with accession number MI0000461 for the stem loopcontaining double stranded microRNA; hsa-miR-145-5p for the mature miR5′ to 3′ strand as set forth in accession number MIMAT0000437; andhsa-miR-145-3p for the 3′ to 5′ complementary strand of a duplex miR-145molecule as set forth by accession number MIMAT0004601. MiR-145 is wellknown and has been studied in detail. See, e.g., Landgraf P, et al.,Cell. 129 pp. 1401-1414 (2007). As stated above for exemplary mimicsmiR-129, miR-140, miR-192, 200a, 200b, 200c, miR-34 and miR-15a, methodsfor creating a miR-145 mimics are known by those of ordinary skill inthe art. Unless otherwise stated, all such modified miR-145 nucleic acidforms are herein considered to be within the scope of the term “miR-145mimic”, as used herein.

Generally, a modified miR-145 (i.e., miR-145 mimic) contains no morethan one, two, three, four, or five additional nucleotides covalentlyappended to the miR-145 native sequence, wherein the additional basesare independently selected from C, U, G, and C, or the additional basesmay be exclusively U. Typically, the miR-145 mimic is used insingle-strand form, but double-stranded versions are also consideredherein.

In some embodiments, at least one of the U bases in the miR-145sequence, whether in the native and/or in an appended portion, is a5-halouracil. The 5-halouracil can be, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil.

In another set of embodiments, precisely one of the U bases in themiR-145 mimic sequence is a 5-halouracil. In a second set ofembodiments, precisely or at least two U bases in the miR-145 sequenceare 5-halouracils. In another set of embodiments, precisely or at leastthree U bases in the miR-145 oligonucleotide sequence are 5-halouracils.In other embodiments, precisely or at least four U bases in the miR-145sequence are 5-halouracils. In other embodiments, precisely or at leastfive U bases in the miR-145 sequence are 5-halouracils. In otherembodiments, precisely or at least six U bases in the miR-145 sequenceare 5-halouracils. In specific embodiments, all of the U bases in themiR-145 sequence, whether in the native and/or in an appended portion,are 5-halouracils.

In an exemplary embodiment, the nucleic acid composition of the presentdisclosure has a modified miR-145 nucleotide sequence ofGU^(F)CCAGU^(F)U^(F)U^(F)U^(F)CCCAGGAAU^(F)CCCU^(F) [SEQ ID NO. 26],wherein U^(F) is a halouracil, specifically 5-fluorouracil.

The U bases that are replaced by 5-halouracils in the miR-145 mimicsequence may be located in an unmodified part of the miR-145 sequence,as provided above, or may be located in one or more uracil bases thatare appended to the native miR-145 sequence, as provided above.

In other embodiments, a seed portion of the native miR-145 nucleotidesequence remains unmodified with a 5-halouracil while one or more (orall) of the remaining U bases in the remainder of the miR-145 nucleotidesequence (non-seed portion) are replaced by a 5-halouracil orcombination thereof.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a miR-194 nucleotide sequencethat has been modified. In some embodiments, the miR-194 nucleotidesequence has been modified by replacing at least one of the U bases witha 5-halouracil.

The term “miR-194”, as used herein, is meant to be synonymous with theterms “microRNA-194” or “miRNA-194” and refers to an oligonucleotidehaving the following nucleotide sequence: UGUAACAGCAACUCCAUGUGGA [SEQ IDNO. 27]. The foregoing nucleotide sequence is herein referred to as amiR-194 unmodified (i.e., “native”) sequence unless otherwise specified.In some embodiments, miR-194 may be referred to in the field ashsa-miR-194 with accession number MI0000488 or MI0000732 for the stemloop containing double stranded microRNA; hsa-miR-94-5p for the maturemiR 5′ to 3′ strand as set forth in accession number MIMAT0000460; andhsa-miR-194-3p for the 3′ to 5′ complementary strand of a duplexmolecule as set forth by accession number MIMAT0004671. MiR-194 is wellknown and has been studied in detail. See, e.g., Lagos-Quintana M, etal., RNA. 9: pp. 175-179 (2003). As is the case for the above, modifiedmicroRNAs, methods for creating a miR-194 mimics are known by those ofordinary skill in the art. Unless otherwise stated, all such modifiedmiR-194 nucleic acid forms are herein considered to be within the scopeof the term “miR-194 mimic”, as used herein.

Generally, a modified miR-194 (i.e., miR-194 mimic) contains no morethan one, two, three, four, or five additional nucleotides covalentlyappended to the miR-194 native sequence, wherein the additional basesare independently selected from C, U, G, and C, or the additional basesmay be exclusively U. Typically, the miR-194 mimic is used insingle-strand form, but double-stranded versions are also consideredherein.

In some embodiments, at least one of the U bases in the miR-194sequence, whether in the native and/or in an appended portion, is a5-halouracil. The 5-halouracil can be, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil.

In another set of embodiments, precisely one of the U bases in themiR-194 mimic sequence is a 5-halouracil. In a second set ofembodiments, precisely or at least two U bases in the miR-194 sequenceare 5-halouracils. In another set of embodiments, precisely or at leastthree U bases in the miR-194 oligonucleotide sequence are 5-halouracils.In other embodiments, precisely or at least four U bases in the miR-194sequence are 5-halouracils. In specific embodiments, all of the U basesin the miR-194 sequence, whether in the native and/or in an appendedportion, are 5-halouracils.

In an exemplary embodiment, the nucleic acid composition of the presentdisclosure has a modified miR-194 nucleotide sequence ofU^(F)GU^(F)AACAGCAACU^(F)CCAU^(F)GU^(F)GGA [SEQ ID NO. 28], whereinU^(F) is a halouracil, specifically 5-fluorouracil.

The U bases that are replaced by 5-halouracils in the miR-194 mimicsequence may be located in an unmodified part of the miR-194 sequence,as provided above, or may be located in one or more uracil bases thatare appended to the native miR-194 sequence, as provided above.

In other embodiments, a seed portion of the native miR-194 nucleotidesequence remains unmodified with a 5-halouracil while one or more (orall) of the remaining U bases in the remainder of the miR-194 nucleotidesequence (non-seed portion) are replaced by a 5-halouracil orcombination thereof.

In another exemplary embodiment, the present disclosure is directed tonucleic acid compositions that include a miR-let-7 nucleotide sequencethat has been modified. In some embodiments, the miR-let-7 nucleotidesequence has been modified by replacing at least one of the U bases witha 5-halouracil.

The term “miR-let-7”, as used herein, is meant to be synonymous with theterms “microRNA-let-7” or “miRNA-let-7” and refers to an oligonucleotidehaving the following nucleotide sequence: UGAGGUAGUAGGUUGUAUAGUU [SEQ IDNO. 29]. The foregoing nucleotide sequence is herein referred to as amiR-let-7 unmodified (i.e., “native”) sequence unless otherwisespecified. In other embodiments, miR-let-7 may also be referred to inthe field as hsa-miR-let-7a-1 with accession number MI0000060 for thestem loop containing double stranded microRNA; hsa-miR-let-7a-5p for themature miR 5′ to 3′ strand as set forth in accession numberMIMAT0000062; and hsa-miR-let-7a-3p for the 3′ to 5′ complementarystrand of a duplex miR-129 molecule as set forth by accession numberMIMAT0004481. MiR-let-7 is well known and has been studied in detail,e.g., Kasashima K, et al., Biochem Biophys Res Commun. 322 pp. 403-410(2004). As stated above for exemplary modified microRNAs describedherein, methods for creating a miR-let-7 mimics are known by those ofordinary skill in the art. Unless otherwise stated, all such modifiedmiR-let-7 nucleic acid forms are herein considered to be within thescope of the term “miR-let-7 mimic”, as used herein.

Generally, a modified miR-let-7 (i.e., miR-let-7 mimic) contains no morethan one, two, three, four, or five additional nucleotides covalentlyappended to the miR-let-7 native sequence, wherein the additional basesare independently selected from C, U, G, and C, or the additional basesmay be exclusively U. Typically, the miR-let-7 mimic is used insingle-strand form, but double-stranded versions are also consideredherein.

In some embodiments, at least one of the U bases in the miR-let-7sequence, whether in the native and/or in an appended portion, is a5-halouracil. The 5-halouracil can be, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil.

In another set of embodiments, precisely one of the U bases in themiR-let-7 mimic sequence is a 5-halouracil. In a second set ofembodiments, precisely or at least two U bases in the miR-let-7 sequenceare 5-halouracils. In another set of embodiments, precisely or at leastthree U bases in the miR-let-7 oligonucleotide sequence are5-halouracils. In other embodiments, precisely or at least four U basesin the miR-let-7 sequence are 5-halouracils. In other embodiments,precisely or at least five U bases in the miR-let-7 sequence are5-halouracils. In other embodiments, precisely or at least six U basesin the miR-let-7 sequence are 5-halouracils. In other embodiments,precisely or at least seven U bases in the miR-let-7 sequence are5-halouracils. In specific embodiments, all of the U bases in themiR-let-7 sequence, whether in the native and/or in an appended portion,are 5-halouracils.

In an exemplary embodiment, the nucleic acid composition of the presentdisclosure has a modified miR-let-7 nucleotide sequence ofU^(F)GAGGU^(F)AGU^(F)AGGU^(F)U^(F)GU^(F)AU^(F)AGU^(F)U^(F) [SEQ ID NO.30], wherein U^(F) is a halouracil, specifically 5-fluorouracil.

The U bases that are replaced by 5-halouracils in the miR-let-7 mimicsequence may be located in an unmodified part of the miR-let-7 sequence,as provided above, or may be located in one or more uracil bases thatare appended to the native miR-let-7 sequence, as provided above.

In other embodiments, a seed portion of the native miR-let-7 nucleotidesequence remains unmodified with a 5-halouracil while one or more (orall) of the remaining U bases in the remainder of the miR-let-7nucleotide sequence (non-seed portion) are replaced by a 5-halouracil orcombination thereof.

In another embodiment, nucleic acid compositions that include a modifiednative miR-489 nucleotide sequence is provided. In some embodiments, themiR-489 nucleotide sequence has been modified by replacing at least oneof the U bases with a 5-halouracil, such as fluorouracil.

The term “miR-489”, as used herein, is meant to be synonymous with theterms “microRNA-489” or “miRNA-489” and refers to an oligonucleotidehaving the following nucleotide sequence: CGACGGCAUAUACACUACAGUG [SEQ IDNO. 31]. The foregoing nucleotide sequence is herein referred to as the‘unmodified” or “native”miR-489 sequence unless otherwise specified.MiR-489 may also be referred to in the field as hsa-miR-489 withaccession number MI0003124 for the stem loop containing double stranded(duplex) microRNA; hsa-miR-489-5p for the mature miR 5′ to 3′ strand asset forth in accession number MIMAT0026605; and hsa-miR-489-3p for the3′ to 5′ complementary strand of the native duplex miR-489 molecule asset forth by accession number MIMAT0002805 and described in SEQ ID NO:31. MiR-489 is well known and has been studied in detail. See, e.g.,Yuan, P. et al. Cancer Res. 77(1) pp. 100-111 (2017). As stated herein,methods for creating modified miR-489 polynucleotide compositions areknown by those of ordinary skill in the art. Unless otherwise stated,all such modified miR-489 nucleic acid forms are herein considered to bewithin the scope of the term “miR-489 mimic” or “modified miR-489”, asused herein.

In certain embodiments, a modified miR-489 can include one, two, three,four, or more additional nucleotides covalently appended to either endthe miR-489 native sequence, wherein the additional bases areindependently selected from C, U, G, and C, or the additional bases maybe exclusively U. Typically, modified miR-489 compositions are used insingle-strand form, but double-stranded versions of the modified miR-489nucleic acid compositions disclosed herein are also provided and the useof such duplex compositions are applicable.

In some embodiments, at least one of the U bases in the miR-489sequence, whether in the native and/or in an appended portion, is a5-halouracil. The 5-halouracil can be, for example, 5-fluorouracil,5-chlorouracil, 5-bromouracil, or 5-iodouracil.

In other embodiments, precisely one of the U bases in the native miR-489sequence is replaced by a 5-halouracil. In a second set of embodiments,precisely or at least two U bases in the miR-489 sequence are5-halouracils. In another set of embodiments, precisely or at leastthree U bases in the miR-489 oligonucleotide sequence are 5-halouracils.In other embodiments, all four U bases in the miR-489 sequence arereplaced by 5-halouracils. In specific embodiments, the modified miR-489nucleic acid composition includes one or more U bases that have beenreplaced by a 5-fluorouracil molecule.

In an exemplary embodiment, the modified nucleic acid composition of thepresent disclosure has a modified miR-489 nucleotide sequence ofCGACGGCAU^(F)AU^(F)ACACU^(F)ACAGU^(F)G [SEQ ID NO. 32], wherein U^(F) isa halouracil, specifically 5-fluorouracil.

In some embodiments, the modified microRNA nucleic acid compositionbinds to a complementary portion of the MDC1 3′ UTR nucleotide sequenceCUAGUUUCAUGCUCAGAUGUCAU as set forth in SEQ ID NO: 33 and acomplementary portion of the SUZ12 3′UTR nucleotide sequenceUAUAUCACUUUUAUUGAUGUCAU as set forth in SEQ ID NO: 34.

In certain embodiments, the modified microRNA nucleic acid compositionof the present disclosure has a modified miR-489 nucleotide sequencethat binds to a complementary portion of the MDC1 3′ UTR nucleotidesequence CUAGUUUCAUGCUCAGAUGUCAU set forth in SEQ ID NO: 33. In aspecific embodiment, the modified microRNA nucleic acid compositionincludes a modified miR-489 nucleotide sequence ofCGACGGCAU^(F)AU^(F)ACACU^(F)ACAGU^(F)G [SEQ ID NO. 32], wherein U^(F) isa 5-fluorouracil, which binds to a complementary portion of the MDC1 3′UTR nucleotide sequence CUAGUUUCAUGCUCAGAUGUCAU set forth in SEQ ID NO:33 to inhibit MDC1 protein expression and/or function.

In other embodiments, the modified microRNA composition has a modifiedmiR-489 nucleotide sequence, which binds to a complementary portion ofthe SUZ12 3′ UTR nucleotide sequence UAUAUCACUUUUAUUGAUGUCAU, as setforth in SEQ ID NO: 34. In a specific embodiment, the modified microRNAnucleic acid composition includes a modified miR-489 nucleotide sequenceof CGACGGCAU^(F)AU^(F)ACACU^(F)ACAGU^(F)G [SEQ ID NO. 32], wherein U^(F)is a 5-fluorouracil, which binds to a complementary portion of the SUZ123′ UTR nucleotide sequence UAUAUCACUUUUAUUGAUGUCAU as set forth in SEQID NO: 34 to inhibit SUZ12 protein expression and/or function.

The U bases that are replaced with 5-halouracils in the modified miR-489nucleotide sequence may be located in an unmodified part of the miR-489sequence, as provided above, or may be located in one or more uracilbases that are appended to the native miR-489 sequence.

In other embodiments, a seed portion of the native miR-489 nucleotidesequence remains unmodified with a 5-halouracil while one or more (orall) of the remaining U bases in the remainder of the miR-489 nucleotidesequence (non-seed portion) are replaced with a 5-halouracil orcombination thereof.

The modified microRNA nucleic acid compositions described herein can besynthesized using any of the well known methods for synthesizing nucleicacids. In particular embodiments, the nucleic acid compositions areproduced by automated oligonucleotide synthesis, such as any of thewell-known processes using phosphoramidite chemistry. To introduce oneor more 5-halouracil bases in a modified miR sequence (e.g., miR-15asequence, miR-140 sequence, miR-192 sequence, miR-502 sequence, miR-506sequence, miR-34 sequence, miR-200a sequence, miR-200b sequence,miR-200c sequence, miR-145 sequence, miR-194 sequence, miR-489 sequenceor the miR-let-7 sequence), a 5-halouracil nucleoside phosphoramiditecan be included as a precursor base, along with the phosphoramiditederivatives of nucleosides containing natural bases (e.g., A, U, G, andC) to be included in the nucleic acid sequence.

In some embodiments, the nucleic acid compositions of the presentdisclosure may be produced biosynthetically, such as by using in vitroRNA transcription from plasmid, PCR fragment, or synthetic DNAtemplates, or by using recombinant (in vivo) RNA expression methods.See, e.g., C. M. Dunham et al., Nature Methods, (2007) 4(7), pp.547-548. The modified microRNA sequences of the present disclosure(e.g., miR-15a sequence, miR-140 sequence, miR-192 sequence, miR-502sequence, miR-506 sequence, miR-34 sequence, miR-200a sequence, miR-200bsequence, miR-200c sequence, miR-145 sequence, miR-194 sequence, miR-489sequence or the miR-let-7 nucleotide sequence) may be further chemicallymodified such as by functionalizing with polyethylene glycol (PEG) or ahydrocarbon or a targeting agent, particularly a cancer cell targetingagent, such as folate, by techniques well known in the art. To includesuch groups, a reactive group (e.g., amino, aldehyde, thiol, orcarboxylate group) that can be used to append a desired functional groupmay first be included in the oligonucleotide sequence. Although suchreactive or functional groups may be incorporated onto the as-producednucleic acid sequence, reactive or functional groups can be morefacilely included by using an automated oligonucleotide synthesis inwhich non-nucleoside phosphoramidites containing reactive groups orreactive precursor groups are included.

Modified MicroRNA Nucleic Acid Formulations

The present disclosure reveals that the modified microRNAs each exhibita potent efficacy as an anti-cancer therapeutic. Notably, each of themodified microRNA nucleic acid compositions tested reduce cancer cellproliferation, tumor growth and development in a dose dependent mannerby inducing cell-cycle arrest in all six cancer types examined.

As such, the present disclosure is also directed to formulations of themodified microRNA nucleic acid compositions described herein. Forexample, the present nucleic acid compositions can be formulated forpharmaceutical uses. In certain embodiments, a formulation is apharmaceutical composition containing a nucleic acid compositiondescribed herein and a pharmaceutically acceptable carrier. In otherembodiments, a formulation of the present disclosure comprises amodified miR-129 nucleic acid, a modified miR-15a nucleic acid, amodified miR-140 nucleic acid, a modified miR-192 nucleic acid, amodified miR-502, a modified miR-506 nucleic acid, a modified miR-34nucleic acid, a modified miR-200a nucleic acid, a modified miR-200b, amodified miR-200c nucleic acid, a modified miR-194 nucleic acid, amodified miR-let-7 nucleic acid, a modified miR-489 nucleic acid, or acombination thereof and a pharmaceutically acceptable carrier.

More specifically, one or more of the modified microRNA nucleic acidsset forth in the following nucleotide sequences can be formulated forpharmaceutical application and use;

[SEQ ID NO. 4]CU^(F)U^(F)U^(F)U^(F)U^(F)GCGGU^(F)CU^(F)GGGCU^(F)U^(F)GC,[SEQ ID NO. 5] CUUUUUGCGGU^(F)CU^(F)GGGCU^(F)U^(F)GC, [SEQ ID NO. 6]U^(F)AGCAGCACAU^(F)AAU^(F)GGU^(F)U^(F)U^(F)GU^(F)G, [SEQ ID NO. 7]UAGCAGCACAU^(F)AAU^(F)GGU^(F)U^(F)U^(F)GU^(F)G, [SEQ ID NO. 9]CAGU^(F)GGUUUUACCCU^(F)AUGGU^(F)AG, [SEQ ID NO. 11]CU^(F)GACCU^(F)AU^(F)GAAU^(F)U^(F)GACAGCC, [SEQ ID NO. 13]AU^(F)CCU^(F)U^(F)GCUAU^(F)CU^(F)GGGU^(F)GCU^(F)A, [SEQ ID NO. 15]U^(F)AU^(F)U^(F)CAGGAAGGU^(F)GU^(F)U^(F)ACU^(F)U^(F)AA, [SEQ ID NO. 16]CAGU^(F)GGU^(F)U^(F)U^(F)U^(F)ACCCU^(F)AU^(F)GGU^(F)AG, [SEQ ID NO. 18]UFGGCAGUFGUFCUFUFAGCUFGGUFUFGUF, [SEQ ID NO. 20]U^(F)AACACU^(F)GU^(F)CU^(F)GGU^(F)AACGAU^(F)GU^(F), [SEQ ID NO. 22]U^(F)AAU^(F)ACU^(F)GCCU^(F)GGU^(F)AAU^(F)GAU^(F)GA, [SEQ ID NO. 24]U^(F)AAU^(F)ACU^(F)GCCGGGU^(F)AAU^(F)GAU^(F)GGA, [SEQ ID NO. 26]GU^(F)CCAGU^(F)U^(F)U^(F)U^(F)CCCAGGAAU^(F)CCCU^(F), [SEQ ID NO. 28]U^(F)GU^(F)AACAGCAACU^(F)CCAU^(F)GU^(F)GGA, [SEQ ID NO. 30]U^(F)GAGGU^(F)AGU^(F)AGGU^(F)U^(F)GU^(F)AU^(F)AGU^(F)U^(F), and[SEQ ID NO. 32] CGACGGCAU^(F)AU^(F)ACACU^(F)ACAGU^(F)G.

The term “pharmaceutically acceptable carrier” is used herein assynonymous with a pharmaceutically acceptable diluent, vehicle, orexcipient. Depending on the type of pharmaceutical composition andintended mode of administration, the nucleic acid composition may bedissolved or suspended (e.g., as an emulsion) in the pharmaceuticallyacceptable carrier. The pharmaceutically acceptable carrier can be anyof those liquid or solid compounds, materials, compositions, and/ordosage forms which are, within the scope of sound medical judgment,suitable for use in contact with tissues of a subject. The carriershould be “acceptable” in the sense of being not injurious to thesubject it is being provided to and is compatible with the otheringredients of the formulation, i.e., does not alter their biological orchemical function.

Some, non-limiting examples, of materials which can serve aspharmaceutically acceptable carriers include: sugars, such as lactose,glucose and sucrose; starches, such as corn starch and potato starch;cellulose and its derivatives, such as sodium carboxymethyl cellulose,ethyl cellulose and cellulose acetate; gelatin; talc; waxes; oils, suchas peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil,corn oil and soybean oil; glycols, such as ethylene glycol and propyleneglycol; polyols, such as glycerin, sorbitol, mannitol and polyethyleneglycol; esters, such as ethyl oleate and ethyl laurate; agar; bufferingagents; water; isotonic saline; pH buffered solutions; and othernon-toxic compatible substances employed in pharmaceutical formulations.The pharmaceutically acceptable carrier may also include a manufacturingaid (e.g., lubricant, talc magnesium, calcium or zinc stearate, orstearic acid), a solvent, or encapsulating material. If desired, certainsweetening and/or flavoring and/or coloring agents may be added. Othersuitable excipients can be found in standard pharmaceutical texts, e.g.in “Remington's Pharmaceutical Sciences”, The Science and Practice ofPharmacy, 19^(th) Ed. Mack Publishing Company, Easton, Pa., (1995).

In some embodiments, the pharmaceutically acceptable carrier may includediluents that increase the bulk of a solid pharmaceutical compositionand make the pharmaceutical dosage form easier for the patient andcaregiver to handle. Diluents for solid compositions include, forexample, microcrystalline cellulose (e.g. Avicer), microfine cellulose,lactose, starch, pregelatinized starch, calcium carbonate, calciumsulfate, sugar, dextrates, dextrin, dextrose, dibasic calcium phosphatedihydrate, tribasic calcium phosphate, kaolin, magnesium carbonate,magnesium oxide, maltodextrin, mannitol, polymethacrylates (e.g.Eudragit®), potassium chloride, powdered cellulose, sodium chloride,sorbitol and talc.

The nucleic acid compositions of the present disclosure may beformulated into compositions and dosage forms according to methods knownin the art. In certain embodiments, the formulated compositions may bespecially formulated for administration in solid or liquid form,including those adapted for the following: (1) oral administration, forexample, tablets, capsules, powders, granules, pastes for application tothe tongue, aqueous or non-aqueous solutions or suspensions, drenches,or syrups; (2) parenteral administration, for example, by subcutaneous,intramuscular or intravenous injection as, for example, a sterilesolution or suspension; (3) topical application, for example, as acream, ointment or spray applied to the skin, lungs, or mucousmembranes; or (4) intravaginally or intrarectally, for example, as apessary, cream or foam; (5) sublingually or buccally; (6) ocularly; (7)transdermally; or (8) nasally.

In some embodiments, the formulations of the present disclosure includea solid pharmaceutical agent that is compacted into a dosage form, suchas a tablet, may include excipients whose functions include helping tobind the active ingredient and other excipients together aftercompression. Binders for solid pharmaceutical compositions includeacacia, alginic acid, carbomer (e.g. carbopol), carboxymethylcellulosesodium, dextrin, ethyl cellulose, gelatin, guar gum, hydrogenatedvegetable oil, hydroxyethyl cellulose, hydroxypropyl cellulose (e.g.Klucel®), hydroxypropyl methyl cellulose (e.g. Methocel), liquidglucose, magnesium aluminum silicate, maltodextrin, methylcellulose,polymethacrylates, povidone (e.g. Kollidon®, Plasdone®), pregelatinizedstarch, sodium alginate and starch.

The dissolution rate of a compacted solid pharmaceutical composition ina subject's stomach may be increased by the addition of a disintegrantto the composition. Disintegrants include alginic acid,carboxymethylcellulose calcium, carboxymethylcellulose sodium (e.g.Ac-Di-Sol®, Primellose®), colloidal silicon dioxide, croscarmellosesodium, crospovidone (e.g. Kollidon®, Polyplasdone®), guar gum,magnesium aluminum silicate, methyl cellulose, microcrystallinecellulose, polacrilin potassium, powdered cellulose, pregelatinizedstarch, sodium alginate, sodium starch glycolate (e.g. Explotab®) andstarch.

Therefore, in certain embodiments, glidants can be added to formulationsto improve the flowability of a non-compacted solid agent and to improvethe accuracy of dosing. Excipients that may function as glidants includecolloidal silicon dioxide, magnesium trisilicate, powdered cellulose,starch, talc and tribasic calcium phosphate.

When a dosage form such as a tablet is made by the compaction of apowdered composition, the composition is subjected to pressure from apunch and dye. Some excipients and active ingredients have a tendency toadhere to the surfaces of the punch and dye, which can cause the productto have pitting and other surface irregularities. A lubricant can beadded to the composition to reduce adhesion and ease the release of theproduct from the dye. Lubricants include magnesium stearate, calciumstearate, glyceryl monostearate, glyceryl palmitostearate, hydrogenatedcastor oil, hydrogenated vegetable oil, mineral oil, polyethyleneglycol, sodium benzoate, sodium lauryl sulfate, sodium stearyl fumarate,stearic acid, talc and zinc stearate.

A formulated pharmaceutical composition for tableting or capsule fillingcan be prepared by wet granulation. In wet granulation, some or all ofthe active ingredients and excipients in powder form are blended andthen further mixed in the presence of a liquid, typically water thatcauses the powders to clump into granules. The granulate is screenedand/or milled, dried and then screened and/or milled to the desiredparticle size. The granulate may then be tableted, or other excipientsmay be added prior to tableting, such as a glidant and/or a lubricant. Atableting composition may be prepared conventionally by dry blending.For example, the blended composition of the actives and excipients maybe compacted into a slug or a sheet and then comminuted into compactedgranules. The compacted granules may subsequently be compressed into atablet.

In other embodiments, as an alternative to dry granulation, a blendedcomposition may be compressed directly into a compacted dosage formusing direct compression techniques. Direct compression produces a moreuniform tablet without granules. Excipients that are particularly wellsuited for direct compression tableting include microcrystallinecellulose, spray dried lactose, dicalcium phosphate dihydrate andcolloidal silica. The proper use of these and other excipients in directcompression tableting is known to those in the art with experience andskill in particular formulation challenges of direct compressiontableting. A capsule filling may include any of the aforementionedblends and granulates that were described with reference to tableting;however, they are not subjected to a final tableting step.

In liquid pharmaceutical compositions of the present disclosure, theagent and any other solid excipients are dissolved or suspended in aliquid carrier such as water, water-for-injection, vegetable oil,alcohol, polyethylene glycol, propylene glycol or glycerin. Liquidpharmaceutical compositions may contain emulsifying agents to disperseuniformly throughout the composition an active ingredient or otherexcipient that is not soluble in the liquid carrier. The liquidformulation may be used as an injectable, enteric, or emollient type offormulation. Emulsifying agents that may be useful in liquidcompositions of the present invention include, for example, gelatin, eggyolk, casein, cholesterol, acacia, tragacanth, chondrus, pectin, methylcellulose, carbomer, cetostearyl alcohol and cetyl alcohol.

In some embodiments, liquid pharmaceutical compositions of the presentdisclosure may also contain a viscosity enhancing agent to improve themouth-feel of the product and/or coat the lining of the gastrointestinaltract. Such agents include acacia, alginic acid bentonite, carbomer,carboxymethylcellulose calcium or sodium, cetostearyl alcohol, methylcellulose, ethylcellulose, gelatin guar gum, hydroxyethyl cellulose,hydroxypropyl cellulose, hydroxypropyl methyl cellulose, maltodextrin,polyvinyl alcohol, povidone, propylene carbonate, propylene glycolalginate, sodium alginate, sodium starch glycolate, starch tragacanthand xanthan gum. In other embodiments, the liquid composition of thepresent disclosure may also contain a buffer, such as gluconic acid,lactic acid, citric acid or acetic acid, sodium gluconate, sodiumlactate, sodium citrate, or sodium acetate.

Sweetening agents, such as sorbitol, saccharin, sodium saccharin,sucrose, aspartame, fructose, mannitol and invert sugar, may be added tocertain formulations of the present disclosure to improve the taste.Flavoring agents and flavor enhancers may make the dosage form morepalatable to the patient. Common flavoring agents and flavor enhancersfor pharmaceutical products that may be included in the composition ofthe present disclosure include maltol, vanillin, ethyl vanillin,menthol, citric acid, fumaric acid, ethyl maltol and tartaric acid.

Preservatives and chelating agents, such as alcohol, sodium benzoate,butylated hydroxy toluene, butylated hydroxyanisole and ethylenediaminetetraacetic acid, may be added at levels safe for ingestion to improvestorage stability. Solid and liquid compositions may also be dyed usingany pharmaceutically acceptable colorant to improve their appearanceand/or facilitate patient identification of the product and unit dosagelevel.

A dosage formulation of the present disclosure may be a capsulecontaining the composition, for example, a powdered or granulated solidcomposition of the disclosure, within either a hard or soft shell. Theshell may be made from gelatin and optionally contain a plasticizer suchas glycerin and sorbitol, and an opacifying agent or colorant.

Methods for Treating Cancer

As stated above, the modified microRNA nucleic acid compositions of thepresent disclosure and formulations thereof show unexpected andexceptional anticancer activity when compared to that exhibited byexogenous expression of a corresponding unmodified native microRNAand/or a known cancer therapy (chemotherapy), such as 5-FU. Therefore,another aspect of the present disclosure provides a method for treatingcancer in a mammal by administering to the mammal an effective amount ofone or more of the modified microRNA nucleic acid compositions of thepresent disclosure, or formulations thereof.

As shown in FIGS. 2A and 8A, exemplary modified microRNA nucleic acidsof the present disclosure, i.e., modified miR-15a and modified MiR-129suppress BCL2 expression and activity in the cancer cells of a subject,which results in an increased amount of available pro-apoptotic proteinswhich ultimately leads to increased cancer cell death. miR-129, forexample, regulates apoptosis by directly targeting BCL2 as well as byimpacting other critical cell death-related proteins. Further, FIG. 2Ashows that miR-129 reduces the expression, and thus activity of E2F3, atranscription factor protein that regulates cell cycle progression andreduces the expression or activity of thymidylate synthase (TS) proteinlevels, which results in increased cellular proliferation and increasedefficacy of chemotherapeutic agents.

Additionally, and as shown in FIGS. 19A and 19B, modified miR-489suppresses SUZ12 and MDC1 protein expression and activity in breastcancer cells by binding to a portion of the SUZ12 and/or MDC1 3′ UTRnucleotide sequence that is complementary to the miR-489 nucleic acidsequence, resulting in a reduction of breast cancer cell proliferationand tumor growth. See FIGS. 2A and 22. Further, FIG. 21B shows thatmodified miR-489 reduces the expression, and thus activity of TS proteinin breast cancer cells.

As shown in FIGS. 12A-12D, 13A-13B and 14A-14, all of the exemplarymodified microRNA's modulate cancer cell proliferation and induce cancercell apoptosis. More specifically, modified miR-15a has been shown toreduce cancer cell proliferation across the following experimentalmodels, pancreatic cancer cells (FIGS. 12A-12B and 14A), lung cancer(FIGS. 12D and 14D), colorectal cancer (FIG. 8B), gastric cancer (FIG.14B), breast cancer (FIG. 14C), and blood cancer, i.e., leukemia (FIG.14E). Furthermore, modified miR-129 has been shown to reduce cancer cellproliferation across the following experimental models, pancreaticcancer cells (FIG. 14A), lung cancer (FIGS. 12C and 14D), colorectalcancer (FIG. 3), gastric cancer (FIG. 14B), breast cancer (FIG. 14C),and blood cancer, i.e., leukemia (FIG. 14E). Modified miR-192 andmodified miR-140 have also shown an ability to reduce cancer cellproliferation across the following experimental models, pancreaticcancer cells (FIG. 14A), lung cancer (FIG. 14D), colorectal cancer(FIGS. 13A-13B), gastric cancer (FIG. 14B), breast cancer (FIG. 14C),and blood cancer, i.e., leukemia (FIG. 14E). Moreover, each modifiedmicroRNAs of the present disclosure (i.e., modified miR-129, miR-15a,miR-192, miR-215, miR-140, miR-502, miR-506, miR-34, miR-200a, miR-200b,miR-200c, miR-145, miR-194 and miR-let-7) inhibits cancer cellproliferation in all of the following experimental cancer models:pancreatic cancer (FIG. 14A), gastric cancer (FIG. 14B), breast cancer(FIG. 14C), lung cancer (FIG. 14D), and blood cancer (FIG. 14E).

In addition, the present modified miR compositions were tested and foundto be therapeutically effective in vivo. For example, FIGS. 7, 11 and 22show that intravenous treatment with exemplary modified microRNA's ofthe present disclosure (e.g., modified miR-129, modified miR-15a andmodified miR-489) effectively treat cancer (e.g., colorectal cancer orbreast cancer) by inhibiting tumor growth and development in vivo.

Therefore, the disclosed methods for treating cancer includeadministering one or more modified nucleic acid compositions of thepresent disclosure (e.g., a modified microRNA, such as modified miR-129nucleic acid, a modified miR-15a nucleic acid, a modified miR-140nucleic acid, a modified miR-192 nucleic acid, a modified miR-502, amodified miR-506 nucleic acid, a modified miR-34 nucleic acid, amodified miR200a nucleic acid, a modified miR-200b nucleic acid, amodified miR-200c nucleic acid, a modified miR-145 nucleic acid, amodified miR-194 nucleic acid, a modified miR-489 nucleic acid, amodified miR-let-7 nucleic acid or a combination thereof) to a subject.In certain embodiments, the nucleic acid composition can be administeredas a formulation that includes a nucleic acid composition and one ormore pharmaceutical carriers.

In specific embodiments, the nucleic acid compositions of the presentdisclosure can be administered in the absence of a delivery vehicle orpharmaceutical carrier (i.e., naked). See, for example, FIGS. 17A-17Band FIGS. 21A-21B.

The term “subject” as used herein refers to any mammal. The mammal canbe any mammal, although the methods herein are more typically directedto humans. The phrase “subject in need thereof” as used herein isincluded within the term subject and refers to any mammalian subject inneed of a treatment, particularly cancer or has a medically determinedelevated risk of a cancerous or pre-cancerous condition. In specificembodiments, the subject includes a human cancer patient.

In some embodiments, the human subject has colorectal cancer or has amedically determined elevated risk of getting colorectal cancer.

In other embodiments, the subject has pancreatic cancer, or has amedically determined elevated risk of getting pancreatic cancer such as,for example, being diagnosed with chronic pancreatitis.

In certain embodiments, a subject of the present disclosure has breastcancer, or has a medically determined elevated risk of getting breastcancer. In specific embodiments, the breast cancer is triple negativebreast cancer, ductal carcinoma or lobal carcinoma. In one embodiment,the subject that is administered a modified microRNA nucleic acidcomposition of the present disclosure has triple negative breast cancer(TNBC).

In some embodiments, the subject has blood cancer or has a medicallydetermined elevated risk of getting blood cancer. In a specificembodiment, the blood cancer is a leukemia. In one embodiment, theleukemia is acute lymphocytic leukemia.

In other embodiments, the subject has gastric cancer, or has a medicallydetermined elevated risk of getting gastric cancer. In one embodiment,the gastric cancer being treated is stomach cancer.

The terms “treatment” “treat” and “treating” are synonymous with theterm “to administer an effective amount”. These terms shall mean themedical management of a subject with the intent to cure, ameliorate,stabilize, reduce one or more symptoms of or prevent a disease,pathological condition, or disorder such as cancer. These terms, areused interchangeably and include the active treatment, that is,treatment directed specifically toward the improvement of a disease,pathological condition, or disorder, and also include causal treatment,that is, treatment directed toward removal of the cause of theassociated disease, pathological condition, or disorder. In addition,treating includes palliative treatment, that is, treatment designed forthe relief of symptoms rather than the curing of the disease,pathological condition, or disorder; preventative treatment, that is,treatment directed to minimizing or partially or completely inhibitingthe development of the associated disease, pathological condition, ordisorder; and supportive treatment, that is, treatment employed tosupplement another specific therapy directed toward the improvement ofthe associated disease, pathological condition, or disorder. It isunderstood that treatment, while intended to cure, ameliorate,stabilize, or prevent a disease, pathological condition, or disorder,need not actually result in the cure, ameliorization, stabilization orprevention. The effects of treatment can be measured or assessed asdescribed herein and as known in the art as is suitable for the disease,pathological condition, or disorder involved. Such measurements andassessments can be made in qualitative and/or quantitiative terms. Thus,for example, characteristics or features of a disease, pathologicalcondition, or disorder and/or symptoms of a disease, pathologicalcondition, or disorder can be reduced to any effect or to any amount. Ina specific embodiment, treatment of a disease, such as a cancer includesinhibiting proliferation of cancer cells. In some embodiments, thetreatment of a cancer can be determined by detecting a reduction in theamount of proliferating cancer cells in a subject, a reduction in tumorgrowth or tumor size.

In certain embodiments, the nucleic acid compositions of the presentdisclosure are used to treat cancer.

The term “cancer”, as used herein, includes any disease caused byuncontrolled division and growth of abnormal cells, including, forexample, the malignant and metastatic growth of tumors. The term“cancer” also includes pre-cancerous conditions or conditionscharacterized by an elevated risk of a cancerous or pre-cancerouscondition. The cancer or pre-cancer (neoplastic condition) can belocated in any part of the body, including the internal organs and skin.As is well known, cancer spreads through a subject by invading thenormal, non-cancerous tissue surrounding the tumor, via the lymph nodesand vessels, and by blood after the tumor invades the veins, capillariesand arteries of a subject. When cancer cells break away from the primarytumor (“metastasize”), secondary tumors arise throughout an afflictedsubject forming metastatic lesions.

Some non-limiting examples of applicable cancer cells for treatmentusing the present methods include the colon, rectum (including anus),stomach, esophageal, kidney, prostate, skin, lungs, breast, pancreas,brain, blood, and liver. The cancer or neoplasm can also include thepresence of one or more carcinomas, sarcomas, lymphomas, blastomas, orteratomas (germ cell tumors). In some embodiments, the cancer may alsobe a form of leukemia.

In particular embodiments, the nucleic acid compositions describedherein are used to treat colorectal (i.e., colon or rectal), pancreatic,breast, gastric, lung or blood cancer in any of their stages, as furtherdescribed below.

For example, there are four stages of colorectal cancer, which aregenerally characterized by the degree of metastasis. In Stage 0 orcarcinoma in situ, abnormal potentially cancerous cells are found in themucosa (innermost layer) of the colon wall. In Stage I, cancerous cellshave formed in the mucosa of the colon wall and have spread to thesubmucosa (layer of tissue under the mucosa) and may have spread to themuscle layer of the colon wall. Stage II is composed of threesubclasses: Stage IIA, wherein the cancerous tissue has spread throughthe muscle layer of the colon wall to the serosa (outermost layer) ofthe colon wall; Stage IIB, wherein the tumor has spread through theserosa of the colon wall but has not spread to nearby organs; and StageIIC, wherein the cancer has spread through the serosa of the colon walland invaded nearby organs. Stage III is also divided into threesubclasses: Stage IIIA, wherein the cancer may have spread through themucosa of the colon wall to the submucosa and muscle layer, and hasspread to one to three nearby lymph nodes or tissues near the lymphnodes; or the cancer has spread through the mucosa to the submucosa andfour to six nearby lymph nodes; Stage IIIB, wherein the tumor has spreadthrough the muscle layer of the colon wall to the serosa or has spreadthrough the serosa but not to nearby organs and the cancer has spread toone to three nearby lymph nodes or to tissues near the lymph nodes; orhas spread to the muscle layer or to the serosa, and to four to sixnearby lymph nodes; or has spread through the mucosa to the submucosaand may have spread to the muscle layer and has spread to seven or morenearby lymph nodes. In Stage IIIC colorectal cancer, the tumor hasspread through the serosa of the colon wall but not to nearby organs andthe cancer has spread to four to six nearby lymph nodes; or the cancerhas spread through the muscle layer to the serosa or has spread throughthe serosa but not to nearby organs and the cancer has spread to sevenor more nearby lymph nodes; or the cancer has spread through the serosato nearby organs and to one or more nearby lymph nodes or to tissuesnear the lymph nodes. Finally, Stage IV colon cancer is divided into twosubclasses: Stage IVA, wherein the cancer has spread through the colonwall and into nearby organs and one organ that is not near the colon orto a distant lymph node; and Stage IVB, wherein the cancer has spreadthrough the colon wall and into nearby organs and more than one organthat is not near the colon or into the lining of the abdominal wall.

Yet another example of tumor staging includes the Dukes classificationsystem for colorectal cancer. Here, the stages are identified as StageA, wherein the tumor is confined to the intestinal wall; Stage B,wherein the tumor exhibits invasion through the bowel but has notinvaded the lymph nodes; Stage C, wherein cancerous cells or tissue isfound within the lymph nodes of a subject; and Stage D, wherein thetumor exhibits widespread metastases into several organs of the subject.

The Astler Coller classification system may alternatively be used. Here,Stage A colorectal cancer is identified as cancer that is only presentin the mucosa of the intestine; Stage B1 whereby the tumor extends intomuscularis propria but does not penetrate through it and the tumor hasnot metastasized into the lymph nodes, Stage B2 colorectal cancer isdenoted by a tumor that penetrates through muscularis propria and thetumor has not metastasized into the lymph nodes; Stage C1 ischaracterized by a tumor that extends into muscularis propria, but doesnot penetrate through it and the tumor has metastasized into the lymphnodes; Stage C2 colorectal cancer is classified as a tumor thatpenetrates through the muscularis propria where the tumor hasmetastasized into the lymph nodes; and Stage D describes a tumor thathas metastasized throughout the organism or subject.

In some embodiments, the treatment methods of the present disclosure aremore particularly directed to cancer subjects exhibiting reduced levelsof miR-129 expression, miR-15a expression, miR-506 expression, miR-502,miR-140 or a combination thereof. In this respect, it is known thatmiR-15a is down-regulated in cancers. See, for example, R I Aqeilan, etal., Cell Death and Differentiation (2010) 17, pp. 215-220. Further, itis known that cancerous cells having reduced levels of miR-129expression are resistant to 5-fluorouracil, as described, e.g., in U.S.Application Pub. No. 2016/0090636, the contents of which areincorporated by reference in their entirety. Additionally, it is knownthat pancreatic cancer cells exhibit reduced levels of miR-506. See,e.g., Li, J, et al. Oncogene. 35 pp. 5501-5514.

In yet another example, the microRNA mimics of the present disclosureare used to treat pancreatic cancer. As shown in FIGS. 14A and 15A-15B,each of modified miR-129, miR-15a, miR-192, miR-215, miR-140, miR-502,miR-506, miR-34, miR-200a, miR-200b, miR-200c, miR-145, miR-194, andmiR-let-7 can be used to treat pancreatic cancer. Pancreatic cancerarises from precursor lesions called pancreatic intraepithelialneoplasia, or PanINs. These lesions are typically located in the smallducts of the exocrine pancreas, and depending on the extent of cytologicatypia may be classified as low-grade dysplasia, moderate dysplasia orhigh-grade dysplasia lesions. Such lesions typically show thatactivating mutations in the KRAS gene present, along with certaininactivating mutations in CDKN2A, TP53 and SMAD4. Collectively, thesegenetic mutations lead to the formation of an infiltrating cancer.Pancreatic cancer is staged based on size of the primary tumor andwhether it has grown outside of the pancreas into surrounding organs;whether the tumor has spread to the nearby lymph nodes, and whether ithas metastasized to other organs of the body (e.g., liver, lungs,abdomen). This information is then combined and used to provide thespecific stage, i.e., 0, 1A, 1B, 2A, 2B, 3 and 4. For stage zero (0),the pancreatic tumor is confined to the top layers of pancreatic ductcells and has not invaded deeper tissues. The primary tumor has notspread outside of the pancreas such as in pancreatic carcinoma in situor pancreatic intraepithelial neoplasia III. A stage 1A pancreatic tumoris typically confined to the pancreas and is 2 cm across or smaller.Further a stage 1A pancreatic tumor has not spread to nearby lymph nodesor distant sites. A stage 1B pancreatic tumor confined to the pancreasand is larger than 2 cm across. A stage 1B pancreatic tumor has notspread to nearby lymph nodes or distant sites. Stage 2A pancreatictumors exhibit a tumor growing outside the pancreas but not into majorblood vessels or nerves, but the cancer has not spread to nearby lymphnodes or distant sites. A subject exhibiting stage 2B pancreatic cancerpresents a tumor is either confined to the pancreas or growing outsidethe pancreas but not into major blood vessels or nerves, but has spreadto nearby lymph nodes. A subject exhibiting stage 3 pancreatic cancerpresents a tumor that is growing outside the pancreas into major bloodvessels or nerves, but has spread to distant sites. Stage 4 pancreaticcancer has metastasized to distant cites, lymph nodes and organs.

In another example, the modified microRNA nucleic acid compositions ofthe present disclosure are used to treat lung cancer. For example, asshown in FIG. 14D each of modified miR-129, miR-15a, miR-192, miR-215,miR-140, miR-502, miR-506, miR-34, miR-200a, miR-200b, miR-200c,miR-145, miR-194, and miR-let-7 can be used to treat lung cancer.Therefore, the present methods include the treatment of non-small celllung cancers, such as squamous cell carcinoma, adenocarcinoma, and largecell carcinoma. Lung cancer often arises from malignancies in thebronchi of the lungs and spreads to other parts of the body, such aslymph nodes. For example, in the case of small cell lung cancer, acancerous lesion is often found in once lung then spreads to the secondlung, the fluid surrounding the lungs (pleura) or neighboring organs.Lung cancer is staged based on size of the primary tumor and whether ithas grown outside of the lung into lymph nodes and whether it hasmetastasized to other organs of the body (e.g., bones, liver, breast,brain). This information is then combined and used to provide thespecific stage, i.e., 0, 1, 2, 3 and 4. For stage zero (0), i.e.,carcinoma in situ, the cancer is small in size and has not spread intodeeper lung tissues or outside the lungs. Stage 1 lung cancer showscancerous cells present in the underlying lung tissues, but the lymphnodes remain unaffected. Stage 2 lung cancer reveals that the cancer hasspread to nearby lymph nodes or into the chest wall. Stage 3 lung canceris classified by a continuous spread from the lungs to the lymph nodesor to nearby structures and organs, such as the heart, trachea andesophagus. Stage 4 lung cancer exhibits metastasized cancer throughoutthe body, which may affect the liver, bones or brain.

In yet another example, the modified microRNA compositions of thepresent disclosure are used to treat breast cancer. As shown in FIGS.14C, 16C, 20A-C and 22, each of modified miR-129, miR-15a, miR-192,miR-215, miR-140, miR-502, miR-506, miR-34, miR-200a, miR-200b,miR-200c, miR-145, miR-194, miR-489 and miR-let-7 can be used to treatbreast cancer. There are several primary forms of breast cancer. Forexample, ductal carcinoma begins in the cells of the ducts. In contrast,lobular carcinoma, which is often found in both breasts, originates inthe lobes or lobules. As such, the present methods include the treatmentof both ductal and lobular breast cancers. More specifically, breastcancers may develop from the presence of one or more genetic mutations,such as HER2, progesterone receptor (PR) or BRACA. As shown in FIGS.16A-16C and 20A-22, the present methods are useful in the treatment ofsuch breast cancers. In a specific embodiment the present methods can beused to treat triple negative breast cancer. See FIG. 22.

In yet another example, the microRNA mimics of the present disclosureare used to treat gastric cancer. As shown in FIG. 14B, each of modifiedmiR-129, miR-15a, miR-192, miR-215, miR-140, miR-502, miR-506, miR-34,miR-200a, miR-200b, miR-200c, miR-145, miR-194, and miR-let-7 can beused to treat gastric cancer. Gastric cancers typically present in twoforms, intestinal adenocarcinomas, which are well differentiated ordiffuse adenocarcinomas, which are poorly differentiated and do not formglandular structures. As such, the present methods include the treatmentof both stomach cancer and gastric adenocarcinoma.

In yet another example, the microRNA mimics of the present disclosureare used to treat blood cancers. As shown in FIGS. 14E and 15C, each ofmodified miR-129, miR-15a, miR-192, miR-215, miR-140, miR-502, miR-506,miR-34, miR-200a, miR-200b, miR-200c, miR-145, miR-194, and miR-let-7can be used to treat blood cancer. There are several types of leukemiaincluding, but not limited to, acute lymphoblastic leukemia (ALL), acutemylogenous leukemia (AML), acute lymphocytic leukemia (ACL), chroniclymphocytic leukemia (CLL) and chronic mylogenous leukemia (CML). Asshown in FIGS. 14E and 15C the present methods are useful in thetreatment of leukemia. As such, the present methods include thetreatment of ALL, ACL, AML, CLL and CIVIL. In a specific embodiment, thepresent methods can be used to treat acute lymphocytic leukemia (ACL).

According to the present disclosure, methods of treating cancer includeadministration of one or more nucleic acid compositions of the presentby any of the routes commonly known in the art. This includes, forexample, (1) oral administration; (2) parenteral administration, forexample, by subcutaneous, intramuscular or intravenous injection; (3)topical administration; or (4) intravaginal or intrarectaladministration; (5) sublingual or buccal administration; (6) ocularadministration; (7) transdermal administration; (8) nasaladministration; and (9) administration directly to the organ or cells inneed thereof.

In specific embodiments, the modified microRNA compositions of thepresent disclosure are administered to a subject by injection. In oneembodiment, a therapeutically effective amount of a modified microRNAcomposition is injected intravenously. In another embodiment, atherapeutically effective amount of a modified microRNA composition isinjected intraperitoneally.

The amount (dosage) of nucleic acid compositions of the presentdisclosure being administered depends on several factors, including thetype and stage of the cancer, presence or absence of an auxiliary oradjuvant drug, and the subject's weight, age, health, and tolerance forthe agent. Depending on these various factors, the dosage may be, forexample, about 2 mg/kg of body weight, about 5 mg/kg of body weight,about 10 mg/kg of body weight, about 15 mg/kg of body weight, about 20mg/kg of body weight, about 25 mg/kg of body weight, about 30 mg/kg ofbody weight, about 40 mg/kg of body weight, about 50 mg/kg of bodyweight, about 60 mg/kg of body weight, about 70 mg/kg of body weight,about 80 mg/kg of body weight, about 90 mg/kg of body weight, about 100mg/kg of body weight, about 125 mg/kg of body weight, about 150 mg/kg ofbody weight, about 175 mg/kg of body weight, about 200 mg/kg of bodyweight, about 250 mg/kg of body weight, about 300 mg/kg of body weight,about 350 mg/kg of body weight, about 400 mg/kg of body weight, about500 mg/kg of body weight, about 600 mg/kg of body weight, about 700mg/kg of body weight, about 800 mg/kg of body weight, about 900 mg/kg ofbody weight, or about 1000 mg/kg of body weight, wherein the term“about” is generally understood to be within ±10%, 5%, 2%, or 1% of theindicated value. The dosage may also be within a range bounded by anytwo of the foregoing values. Routine experimentation may be used todetermine the appropriate dosage regimen for each patient by monitoringthe compound's effect on the cancerous or pre-cancerous condition, oreffect on microRNA expression level or activity (e.g., miR-15a,miR-200a, miR-200b, miR-200c, miR-145, miR-194, miR-34, miR-let-7,miR-129, miR-140, miR-192, miR-489, miR-502, miR-506), or effect on atarget thereof, such as SUZ12 level or activity, MDC1 level or activity,BCL2 level or activity, or effect on TS level or activity, or effect onE2F3 level or the disease pathology, all of which can be frequently andeasily monitored according to methods known in the art. Depending on thevarious factors discussed above, any of the above exemplary doses ofnucleic acid can be administered once, twice, or multiple times per day.

In one embodiment, a modified microRNA composition administered to asubject having cancer, such as breast cancer, binds to a complementaryportion of the MDC1 3′ UTR nucleotide sequence CUAGUUUCAUGCUCAGAUGUCAUset forth in SEQ ID NO: 33 or a complementary portion of the SUZ12 3′UTRnucleotide sequence UAUAUCACUUUUAUUGAUGUCAU as set forth in SEQ ID NO:34. In certain embodiments, the modified microRNA compositionadministered to a subject having breast cancer has a modified miR-489nucleotide sequence, which binds to a complementary portion of the MDC13′ UTR nucleotide sequence CUAGUUUCAUGCUCAGAUGUCAU set forth in SEQ IDNO: 33. In a specific embodiment, the modified microRNA nucleic acidcomposition includes a modified miR-489 nucleotide sequence ofCGACGGCAU^(F)AU^(F)ACACU^(F)ACAGU^(F)G [SEQ ID NO. 32], wherein U^(F) isa 5-fluorouracil, which binds to a complementary portion of the MDC1 3′UTR nucleotide sequence CUAGUUUCAUGCUCAGAUGUCAU set forth in SEQ ID NO:33 to inhibit MDC1 protein expression and/or function. In otherembodiments, the modified microRNA composition administered to a subjecthaving breast cancer has a modified miR-489 nucleotide sequence, whichbinds to a complementary portion of the SUZ12 3′ UTR nucleotide sequenceUAUAUCACUUUUAUUGAUGUCAU as set forth in SEQ ID NO: 34. In a specificembodiment, the modified microRNA nucleic acid composition includes amodified miR-489 nucleotide sequence ofCGACGGCAU^(F)AU^(F)ACACU^(F)ACAGU^(F)G [SEQ ID NO. 32], wherein U^(F) isa 5-fluorouracil, which binds to a complementary portion of the SUZ12 3′UTR nucleotide sequence UAUAUCACUUUUAUUGAUGUCAU as set forth in SEQ IDNO: 34 to inhibit SUZ12 protein expression and/or function.

Mediator of DNA damage checkpoint protein 1 (MDC1) has been identifiedas an upstream mediator in the cellular response to DNA damage. See Zou,R. et al. Int J Biol Sci 11(9) pp. 992-1005 (2015). MDC1 is known in theart to have the following DNA, RNA and amino acid sequences,respectively: Gene ID No. 9656, NM 014641.3 and NP 055456.2.Additionally, several MDC1 protein isoforms are known to those ofordinary skill in the art, such as including isoform X3 (XM 005249494.5,XP 005249551.1), isoform X4 as set forth in XM 017011520.2 and XP016867009.1, and isoform X7 as set forth in XM 017011521.2 and XP016867010.1. As set forth herein, the MDC1 gene sequence includes a 3′untranslated region (UTR) including the following nucleotide sequence,from 5′ to 3′, CUAGUUUCAUGCUCAGAUGUCAU set forth in SEQ ID NO: 33.

Suppressor of zest 12 (SUZ12) is one of the core polycomb repressivecomplex 2 (PRC2) components identified as an oncogene. See, e.g., Wu, Y.et al., J Cell Mol Med. 22(7) pp. 3582-3594 (2018). SUZ12 is known inthe art to have the following DNA, RNA and amino acid sequences,respectively: Gene ID No. 23512 (NG 009237.1), NM 015355.4 and NP056170.2 as well as the isoforms such as those set forth in NM001321207.2 and NP_001308136.1. As set forth herein, the SUZ12 genesequence includes a 3′ UTR including the following nucleotide sequence,from 5′ to 3′, UAUAUCACUUUUAUUGAUGUCAU as set forth in SEQ ID NO: 34.

The ability of the nucleic acid compositions described herein, andoptionally, any additional chemotherapeutic agent for use with thecurrent methods can be determined using pharmacological models wellknown in the art, such as cytotoxic assays, apoptosis staining assays,xenograft assays, and binding assays.

The nucleic acid compositions described herein may or may not also beco-administered with one or more chemotherapeutic agents, which may beauxiliary or adjuvant drugs different from a nucleic compositiondescribed herein.

As used herein, “chemotherapy” or the phrase a “chemotherapeutic agent”is an agent useful in the treatment of cancer. Chemotherapeutic agentsuseful in conjunction with the methods described herein include, forexample, any agent that modulates BCL2, E2F3 or TS, either directly orindirectly. Examples of chemotherapeutic agents include:anti-metabolites such as methotrexate and fluoropyrimidine-basedpyrimidine antagonist, 5-fluorouracil (5-FU) (Carac® cream, Efudex®,Fluoroplex®, Adrucil®) and S-1; antifolates, including polyglutamatableantifolate compounds; raltitrexed (Tomudex®), GW1843 and pemetrexed(Alimta®) and non-polyglutamatable antifolate compounds; nolatrexed(Thymitaq®), plevitrexed, BGC945; folic acid analogs such as denopterin,methotrexate, pteropterin, trimetrexate; and purine analogs such asfludarabine, 6-mercaptopurine, thiamiprine, thioguanine; pyrimidineanalogs such as ancitabine, azacitidine, 6-azauridine, carmofur,cytarabine, dideoxyuridine, doxifluridine, enocitabine, floxuridine. Ina specific embodiment of the current disclosure, the chemotherapeuticagent is a compound capable of inhibiting the expression or activity ofgenes, or gene products involved in signaling pathways implicated inaberrant cell proliferation or apoptosis, such as, for example, YAP1,BMI1, DCLK1, BCL2, SUZ12, MDC, thymidylate synthase or E2F3; andpharmaceutically acceptable salts, acids or derivatives of any of theabove.

In other embodiments, the chemotherapy can be any of the followingcancer drugs, such as one or more of methotrexate, doxorubicin,cyclophosphamide, cis-platin, oxaliplatin, bleomycine, vinblastine,gemcitabine, vincristine, epirubicin, folinic acid, paclitaxel, anddocetaxel. The chemotherapeutic agent may be administered before,during, or after commencing therapy with the nucleic acid composition.

In some embodiments, the chemotherapeutic agent is an anti-cancer drug,or a tissue sensitizer or other promoter for an anti-cancer drug. Insome embodiments, the co-drug may be another nucleic acid, or anothermiRNA, such as a microRNA mimic of the present disclosure, gemctiabineor free 5-FU.

In a specific embodiment, the other nucleic acid is a short hairpin RNA(shRNA), siRNA, or nucleic acid complementary to a portion of the BCL23′UTR.

In some embodiments, the chemotherapeutic agent is a co-drug.

E2F transcription factor 3, E2F3 (RefSeq NG_029591.1, NM_001243076.2,NP_001230005.1) is a transcription factor that binds DNA and interactswith effector proteins, including but not limited to, retinoblastomaprotein to regulate the expression of genes involved in cell cycleregulation. Therefore, any drug that inhibits the expression of E2F3 maybe considered herein as a co-drug.

B-cell lymphoma 2 (BCL2), (RefSeq NG_009361.1, NM_000633, NP_000624)including isoform α (NM_000633.2, NP_000624.2) and β NM_000657.2,NP_000648.2 thereof, are encoded by the Bcl-2 gene, which is a member ofthe BCL2 family of regulator proteins that regulate mitochondriaregulated cell death via the intrinsic apoptosis pathway. BCL2 is anintegral outer mitochondrial membrane protein that blocks the apoptoticdeath of cell cells by binding BAD and BAK proteins. Non-limitingexamples of BCL2 inhibitors include antisense oligonucleotides, such asOblimersen (Genasense; Genta Inc.), BH3 mimetic small moleculeinhibitors including, ABT-737 (Abbott Laboratories, Inc.), ABT-199(Abbott Laboratories, Inc.), and Obatoclax (Cephalon Inc.). Any drugthat inhibits the expression of BCL2 may be considered herein as aco-drug.

Thymidylate synthase (RefSeq: NG_028255.1, NM_001071.2, NP_001062.1) isa ubiquitous enzyme, which catalyses the essential methylation of dUMPto generate dTMP, one of the four bases which make up DNA. The reactionrequires CH H₄-folate as a cofactor, both as a methyl group donor, anduniquely, as a reductant. The constant requirement for CH H₄-folatemeans that thymidylate synthase activity is strongly linked to theactivity of the two enzymes responsible for replenishing the cellularfolate pool: dihydrofolate reductase and serine transhydroxymethylase.Thymidylate synthase is a homodimer of 30-35 kDa subunits. The activesite binds both the folate cofactor and the dUMP substratesimultaneously, with the dUMP covalently bonded to the enzyme via anucleophilic cysteine residue (See, Carreras et al, Annu. Rev. Biochem.,(1995) 64:721-762). The thymidylate synthase reaction is a crucial partof the pyrimidine biosynthesis pathway which generates dCTP and dTTP forincorporation into DNA. This reaction is required for DNA replicationand cell growth. Thymidylate synthase activity is therefore required byall rapidly dividing cells such as cancer cells. Due to its associationwith DNA synthesis, and therefore, cellular replication, thymidylatesynthase has been the target for anti-cancer drugs for many years.Non-limiting examples of thymidylate synthase inhibitors include folateand dUMP analogs, such as 5-fluorouracil (5-FU). Any drug that inhibitsthe expression of thymidylate synthase may be considered herein as aco-drug.

If desired, the administration of the nucleic acid composition describedherein may be combined with one or more non-drug therapies, such as, forexample, radiotherapy, and/or surgery. As well known in the art,radiation therapy and/or administration of the chemotherapeutic agent(in this case, the nucleic acid composition described herein, andoptionally, any additional chemotherapeutic agent) may be given beforesurgery to, for example, shrink a tumor or stop the spread of the cancerbefore the surgery. As also well known in the art, radiation therapyand/or administration of the chemotherapeutic agent may be given aftersurgery to destroy any remaining cancer.

Examples have been set forth below for the purpose of illustration andto describe certain specific embodiments of the invention. However, thescope of this invention is not to be in any way limited by the examplesset forth herein.

EXAMPLES Example 1. Materials and Methods

modified microRNAs: the 5-FU modified miRs were synthesized by anautomated oligonucleotide synthesis process and purified by HPLC. Thetwo strands were annealed to make the mature modified 5-FU-miRs of thepresent disclosure. More specifically, a process referred to as “2′-ACERNA synthesis” was used. The 2′-ACE RNA synthesis is based on aprotecting group scheme in which a silylether is employed to protect the5′-hydroxyl group in combination with an acid-labile orthoesterprotecting group on the 2′-hydroxy (2′-ACE). This combination ofprotecting groups is then used with standard phosphoramidite solid-phasesynthesis technology. See, for example, S. A. Scaringe, F. E. Wincott,and M. H. Caruthers, J. Am. Chem. Soc., 120 (45), 11820-11821 (1998);International PCT Application W O/1996/041809; M. D. Matteucci, M. H.Caruthers, J. Am. Chem. Soc., 103, 3185-3191 (1981); S. L. Beaucage, M.H. Caruthers, Tetrahedron Lett. 22, 1859-1862 (1981), the entirecontents of each of which are expressly incorporated herein.

The exemplary modified miR-15a nucleic acid, modified miR-140 nucleicacid, modified miR-192 nucleic acid, modified miR-502, modified miR-506nucleic acid modified miR-34 nucleic acid, modified miR-194 nucleicacid, modified miR-200a, modified miR-200b, modified miR-200c nucleicacid, modified miR-145 nucleic acid, modified miR-let-7 nucleic acid orany other modified microRNAs that replace uracil with a 5-halouracil canbe synthesized in the same manner as set forth herein.

Some exemplary structures of the protected and functionalizedribonucleoside phosphoramidites currently in use are shown below:

Cell culture. The human colon cancer cell lines HCT116, RKO, SW480,SW620, and the normal colon cell line CCD 841 CoN, pancreatic cancercell lines ASPC-1, HS766T, Panc-1, AGS gastric cancer cell line, SKBR3and MDA-MB-231 breast cancer cells, REH acute lymphocytic cell lines,and lung cancer cell line A549, were obtained from the American TypeCulture Collection (ATCC) and maintained in various types of media. Forexample, McCoy's 5A medium (SKBR3, HCT-116), DMEM (RKO, HS766T, SW480,SW620) and MEM (CCD 841 CoN), RPMI-1640 (REH and APSC-1) and F-12K media(AGS, A549). Media was supplemented with 10% fetal bovine serum (ThermoFischer).

For transfections, 1×10⁵ cells were plated in six-well plates andtransfected with 100 nM of control non-specific miRNA (Thermo Fischer),a modified microRNA, or exogenous native microRNA after 24 hours usingOligofectamine (Thermo Fischer) following the manufacturer's protocols.For reagent free transfection, cells were plated in 6 well plates at(1×10⁵) cells per well. Twenty-four hours later 100 pmol miRNA (Control,miR-15a, Mimic-1) were diluted in Optimem (Thermo Fischer) and added tothe plate. Media was changed after 24 hours. Media was supplemented with10% fetal bovine serum (Thermo Fischer). Briefly, cells were cultured ingrowth media (DMEM/F12 supplemented with B27, 10 ng/mL bFGF, and 20ng/mL EGF (Life Technologies) in ultra-low attachment flasks) for up to6 days. The spheroid cells were maintained by collection through gentlecentrifugation, dissociation to single cells and replating.

Western immunoblot analysis: Forty-eight hours after transfection, equalamounts of protein (15 μg) extracted from cells lysed in RIPA bufferwith protease inhibitor (Sigma) and were separated on 10%-12% sodiumdodecyl sulfate-polyacrylamide gels using standard procedures. Theprimary antibodies used for the analysis were rabbit anti-YAP1monoclonal antibody (1:10000) (Cell Signaling Technologies), anti-DLCK1(1:500) (Abcam), anti-BCL2 (1:500) (NeoMarkers), anti-MDC1 (1:500),anti-SUZ12 (1:500), anti-pChk-1 (1:500), anti beta-actin (1:500),anti-BMI-1 (1:10000) (Cell Signaling Technologies), mouse anti-human TSantibody (1:500), anti-α-tubulin (1:50000) (Santa Cruz Biotech Inc.),anti-GAPDH (1:100000) (Santa Cruz Biotech Inc.), anti-E2F3 (1:500)(Santa Cruz Biotech Inc.), Horseradish peroxidase-conjugated antibodiesagainst mouse or rabbit (1:5000, Santa Cruz Biotech Inc.) were used asthe secondary antibodies. Protein bands were visualized withautoradiography film using SuperSignal West Pico ChemiluminescentSubstrate (Thermo Fischer). Western blot density was quantified usingImage J software.

Cell proliferation assay: Twenty-four hours after transfection, cellswere seeded in 96-well plates at a density of 2000 cells per well. Thecell proliferation assay was performed on days 1 to 5 by incubating 10μl WST-1 (Roche Applied Science, Mannheim, Germany) in the culturemedium for 1 h and reading the absorbance at 450 and 630 nm. The cellproliferation rate was calculated by subtracting the absorbance at 450nm from the absorbance at 630 nm. Experiments for the cell proliferationassay were performed at least three times. The O.D. was calculated bysubtracting the absorbance at 630 nm from that at 450 nm. Proliferationexperiments were performed three times.

Anchorage-independent proliferation was studied to determine cancer cellcolony forming ability. Cancer cells were trypsinized and counted and atotal of 1×10⁵ cells per well were transfected in 6-well plates with 25nM modified microRNA or native miRs or a negative control miRNA witholigofectamine, and 6 hours after transfection, cells were recounted. Atotal of 20,000 cells in 0.35% agar (Bacto Agar; Becton Dickinson) werelayered on top of 1 mL of a solidified 0.6% agar layer in a 35-mm dish.Growth media with B27, 10 ng/mL bFGF, and 20 ng/mL EGF were included inboth layers. After 2 weeks of incubation, colonies more than 50 mm indiameter were counted.

Cell cycle analysis: Twenty-four hours after transfection, cells wereharvested and resuspended at 0.5 to 1×10⁶ cells/mL in modified Krishan'sbuffer supplemented with 0.02 mg/mL RNase H and 0.05 mg/mL propidiumiodide. Stained cells were detected by flow cytometry and results wereanalyzed with Modfit LT™ software. The experiments for cell cycleanalysis were performed at least three times.

Apoptosis Assay. To distinguish between early and late apoptosis, afluorescein isothiocyanate (FITC)—Annexin assay was done (BectonDickinson). HCT116, RKO, SW480 and SW620 cells were plated into 6 wellplates (1×10⁵) cells per well, after 24 h, cells were transfected with25 nM modified miRNAs using Oligofectamine. Forty-eight hours aftertransfection, cells were harvested, stained with propidium iodide andanti-annexin-V antibody (Annexin V-FITC Apoptosis Detection kit,Invitrogen, CA, USA) following the manufacturer's protocol, and stainedcells were detected by flow cytometry.

5-FU treatment and cytotoxicity assay: Twenty-four hours aftertransfection, cancer cells were plated in 96-well plates at 2×10³ cellsper well in triplicates in 100 μL of medium. After 24 hours, freshmedium containing 2 μM 5-FU alone, 50 nM native microRNA, 50 nM modifiedmicroRNA (e.g., modified miR-129), or a combination of 2 mM 5-FU with 50nM a modified microRNA of the present disclosure e.g., modified miR-129,were added, and cells were cultured for an additional 72 hours. Cellviability was measured using the WST-1 assay.

Lentivirus production: Briefly, 1.5×10⁶ 293 T cells were plated in a10-cm dish with 10 mL of DMEM+10% FBS. Two days later, pEZX-MR03, alentiviral plasmid, expressing miR-129 or hsa-miR-15a, was transfectedwith Lenti-Pac HIV expression packaging kit following the manufacturer'sprotocol. Forty-eight hours later, the virus was harvested andconcentrated with Lenti-Pac lentivirus concentration solution. Then thetiter of the virus (approximately 1011 virus particles/ml) wasdetermined with Lenti-Pac™ HIV qRT-PCR titration kit. In addition,serial dilution of the virus (0.1 μL, 0.5 μL, 2 μL, 10 μL, 50 μL) wasused to transduce 5×10⁴ HCT116 CSC to determine the transductionefficiency. The lowest concentration (2 μL) to achieve 100% positiveexpression was used to infect the cells for mouse in vivo treatmentexperiments.

Real-time qRT-PCR analysis of nucleic acid expression. The expressionlevels of microRNAs in cancer cells were quantified. Briefly, theprimers specific to the microRNA of interest and an internal controlRNU44 gene were purchased from Ambion. cDNA synthesis was performed bythe High Capacity cDNA Synthesis Kit (Applied Biosystems) withmiRNA-specific primers. Real-time qRT-PCR was carried out on an AppliedBiosystems 7500 Real-Time PCR machine with miRNA-specific primers byTaqMan Gene Expression Assay (Applied Biosystems). Expression level ofthe exemplary miRs of the present disclosure was calculated by the AACTmethod based on the internal control RNU44, normalized to the controlgroup and plotted as relative quantification.

Human cancer stem cell profiler: RNAs were extracted from cancer cellstransfected with either exemplary microRNAs of the present disclosure ornegative miRNA using TRIzol reagent (Thermo Fischer) in accordance withthe manufacturer's protocol. RNAs were transcribed to first-strand cDNAusing the RT2 First Strand Kit (Qiagen). Next, the cDNA is mixed withRT2 SYBR Green Mastermix (Qiagen), and this mixture is aliquoted intothe wells of the Human Cancer Stem Cells RT2 Profiler PCR Array(Qiagen). Applied Biosystems 7500 Real-Time PCR machine was used forqRT-PCR (Applied Biosystems), and relative expression values weredetermined using the AACT method.

Mouse subcutaneous tumor implantation model: Two days before injection,HCT116 colorectal cancer stem cells or MDA-MB-231 breast cancer cellswere plated at 5×10⁵/well in a 6-well ultra low attachment plate. 20 μLof the virus or 100 pmole exemplary modified miR-129 or modified miR-15awere used to transduce or transfect cells. Forty-eight hours later,cells were collected and re-suspended at 10⁶/ml in DMEM/F12 knockoutmedia with 30% matrigel. Ten-twelve week-old NOD/SCID mice (JacksonLaboratories, Bar Harbor, Mass., USA) were used for tumor implantation.The mice were anesthetized by isoflurane inhalation. 100 μL of cellsuspension was injected subcutaneously into both sides of the lower backarea. The tumor size was measured using a caliper, and tumor volume wascalculated using the formula V=length×width/2.

For in vivo miRNA delivery experiments, colon cancer cells were createdthat expressed the lenti-luc reporter gene by infecting parental HCT116cells with a recombinant lentivirus. Luciferase-expressing HCT116 cells(2.0×10⁶ cells per mouse) were suspended in 0.1 mL of PBS solution andwas injected through tail vein of each mouse. Two weeks after injectionof colon cancer cells, mice were treated via tail vein injection with 40μg of negative control or modified miR(s) packaged with in vivo-jetPEI(Polyplus Transfection). Mice were treated every other day for 2 weeks(8 times). Following treatment, mice were screened using IVIS SpectrumIn vivo Imaging System (IVIS) (PerkinElmer).

RNA isolation: For mouse xenografts, sectioned tissues weredeparaffinized, hydrated, and digested with proteinase K, respectively.Subsequently, total RNA was isolated using the TRIzol® reagent. TotalRNA was also isolated from clinical specimens by the TRIzol®)-basedapproach.

Statistical analysis All experiments were repeated at least three times.All statistical analyses were performed with SigmaPlot software. Thestatistical significance between two groups was determined usingStudent's t-test (paired t-test for clinical samples, and unpairedt-test for all other samples). For comparison of more than two groups,one-way ANOVA followed by a Bonferroni-Dunn test was used. Data wereexpressed as mean±standard error of the mean (SEM). The statisticalsignificance is either described in figure legends, or indicated withasterisks (*). *=P<0.05; **=P<0.01; ***=P<0.001.

Example 2: Modified MicroRNAs of the Present Disclosure have Anti-CancerActivity

As shown in FIGS. 3, 8B, 12A-D 13A-B, 14A-E, 15A-C and 20A-B, themodified miRNAs (modified miR: 129, 15a, 192 (215), 140, 502, 34, 194,200a, 200b, 200c, 489,145, let-7 and 506) are effective in inhibitingcolon cancer, blood cancer, breast cancer, gastric cancer, pancreaticcancer, and lung cancer cell proliferation when compared to one orcontrols (i.e, non-specific microRNA, non-modified miRNA precursor, orvehicle alone). In addition, the modified miRNAs can be delivered intocancer cells without the transfection reagent (as shown in FIGS. 17A-17Band 21A-21B). Notably, the results show that cancer cell proliferationacross several different colorectal cancer cell lines, pancreatic cancercell lines, breast cancer cell lines, lung cancer cell lines, a gastriccancer cell line and a leukemia cell line is inhibited significantlywhen compared to cancer cells treated with control microRNAs or vehiclealone.

Example 3: Modified miR-129 Nucleic Acids have Anti-Cancer Activity

In the following experiments, 5-FU was incorporated into miR-129. In oneexperiment, all U bases in miR-129 were replaced with 5-FU, as shown inthe structure provided in FIG. 1A, where “U^(F)” represents5-fluorouracil or other 5-halouracil. In another experiment, all Ubases, except the seed region of the miR-129, were replaced with 5-FU,as shown in the structure provided in FIG. 1B.

Analysis of target specificity: The results of Western immunoblotexperiments in colon cancer HCT-116 cells demonstrate that the exemplarymodified miR-129 polynucleotides of the present disclosure were able toretain their target specificity to TS, BCL2 and E2F3 via. The resultsare shown in FIGS. 2A and 2B, which shows the results for the modifiedmiR-129 nucleic acid having all U bases were replaced with 5-FU, asobtained by two separate operators as set forth in SEQ ID. NO: 4. Offurther significance, the exemplary miR-129 mimics were found to be morepotent than unmodified (control) miR-129 in reducing the expressionlevels of TS, BCL2 and E2F3.

Function enhancement of modified microRNAs of the present disclosure.The impact of an exemplary modified miR-129 on colon cancer cellproliferation was compared to that of native miR-129. The results showthat, at 50 nM concentration, 5-FU-miR-129 can suppress HCT-116 tumorcell growth completely. Moreover, as shown by the results in FIG. 3,5-FU-miR-129 is much more potent than the native miR-129, therebyproviding a significantly higher inhibitory effect. Such inhibition isspecific, as the scramble control miR has no effect on cellproliferation.

Next, the potencies of modified miR-129 and 5-FU on cell proliferationwere compared using HCT-116 colon cancer cells. As shown by the resultsprovided in FIG. 4, 50 nM (40-fold less than 5-FU) of modified miR-129is unexpectedly much more potent than 2 μM 5-FU in inhibiting tumor cellproliferation.

Exemplary modified microRNAs of the present disclosure induce apoptosisin colon cancer cells. With BCL2 being an important target of miR-129,the impact of a modified miR of the present disclosure on apoptosis wasinvestigated. Specifically, cell death was quantified using an apoptosisassay in HCT116, RKO, SW480, and SW620 colon cancer cells transfectedwith negative control miRNA, native miR-129 or an exemplary miR-129mimic of SEQ ID NO: 4. Results show that the miR-129 mimic was able toinduce apoptosis by 2 to 30-fold in all 4 colon cancer cell lines via afluorescence-activated cell sorting (FACS)-based FITC-Annexin assaycompared to the native miR-129 and negative control miRNA (FIG. 5A).

miR-129 mimic trigger G1/S cell cycle check point control. Cell cycleanalysis was performed using flow cytometry in HCT-116 cells treatedwith scramble control, miR-129 precursor, and an exemplary miR-129mimic. As shown in FIG. 5B, cell cycle analysis revealed that themiR-129 mimic impacts colon cancer cell growth by inducing G1 arrest,and such impact is much more potent (more than two-fold) than nativemiR-129.

miR-129 mimics eliminated chemotherapy resistant colon cancer stemcells. To determine the impact of certain exemplary modified microRNAsof the present disclosure (i.e., miR-129 mimics) on 5-FU resistant coloncancer stem cells, HCT116 derived colon cancer stem cells were treatedwith various concentrations of Mimic-1 or 5-FU. The data shown in FIG. 6reveal that exemplary microRNA mimics of the present disclosure are ableto eliminate 5-FU resistant colon cancer stem cells by over 80% at 100nM concentration, while a lethal dose of 5-FU at 100 μM has minimaleffect on tumor stem cell viability.

Taken together, these results show that exemplary modified microRNApolynucleotides of the present disclosure were able to inhibit cellproliferation of HCT116 colon cancer stem cells (FIG. 6). Suchinhibitory effect by modified miR-129 was much more potent than nativemiR-129, as proliferation was nearly completely blocked with 25 nMmiR-129 on day 6 (FIG. 6). We also demonstrated the impact of treatmentof cells with modified miR-129 on anchorage independent cell growthusing a soft agar assay. The modified miR-129 treated colon cancer stemcells and formed no visible spheres compared to cells treated with thenative miR-129 or control miRNA (similar to those seen in FIG. 10).

miR-129 mimics inhibit colon cancer metastasis in vivo. The therapeuticimpact of modifying miR-129 nucleic acids was evaluated using a coloncancer metastasis model. Two weeks after establishing metastasis, 40 μgof a miR-129 nucleic acid of SEQ ID NO; 4 was delivered by intravenousinjection with treatment frequency of one injection every other day fortwo weeks.

The results shown in FIG. 7 reveal that modified microRNA-129 inhibitscolon cancer metastasis while negative control miRNA has no effect,while exhibiting no toxic side effects.

Example 4. Exemplary Modified miRs and the Anti-Cancer Activity Thereof

Exemplary modified miR-15a compositions have anti-cancer activity. Asshown in FIG. 1C and FIG. 1D, exemplary modified miR-15a mimics in whichall of the uracil bases (FIG. 1C) or only uracil bases that in thenon-seed region (FIG. 1D) of the miR-15a nucleic acid sequence werereplaced with a 5-halouracil (i.e., 5-flurouracil) were synthesized asset forth above.

Three days following transfection of the exemplary modified miR-15a setforth in FIG. 1C into HCT-116 colon cancer stem cells, protein wascollected and Western Bloting was performed to confirm that the modifiedmiR-15a nucleic acid compositions of the present disclosure maintainedthe ability to regulate key miR-15a targets. As shown in FIG. 8A,miR-15a targets YAP1, BMI1, DCLK1 and BCL2 exhibited protein levels thatwere reduced upon transfection by either the unmodified miR-15a(native-miR15a) or modified miR-15a compositions, indicating that the5-halouracil modification did not inhibit the ability of miR-15a toregulate their targets in cells.

Modified miR-15a has increased therapeutic efficacy in vitro. In orderto determine whether the modified miR-15a compositions of the presentdisclosure demonstrated increased potency in colon cancer cell linescompared to unmodified miR-15a, HCT-116 colon cancer cells weretransfected with a negative control (non-specific oligonucleotide),unmodified miR-15a or the exemplary modified miR-15a compositions setforth in FIG. 1C.

A WST-1 assay was used to assess cancer cell proliferation. As shown inFIG. 8B, six days after transfection, unmodified miR-15a had decreasedcell proliferation by 53% compared to control. In the case of modifiedmiR-15a, cell proliferation was decreased by 84%. Taken together, theexperimental results show that modified miR-15a is more effective atdecreasing cancer cell proliferation compared to the unmodified miR-15a.

Modified miR-15a nucleic acids were also analyzed for their ability toinhibit cell cycle progression in cancer cells. FIG. 9A shows thatunmodified miR-15a induced cell cycle arrest and lead to about 3-foldincrease in the G1/S ratio. FIG. 9A also shows that the exemplarymodified miR-15a compositions of the present disclosure were moreeffective in stopping cell cycle progression when compared to theirnative counterpart. For example, a 7-fold increase in the G1/S ratio wasexhibited by cells expressing the exemplary modified miR-15a nucleicacids of the present disclosure when compared to the control. Therefore,modified miR-15a is more effective at inducing cell cycle arrest incolon cancer cells than unmodified miR-15a.

Similarly, modified miR-let-7 and modified miR-145 were more effectivein stopping cell cycle progression than negative controls. See FIG. 9B.For example, a significant fold increase in the G1/S ratio was exhibitedby cells expressing the exemplary modified miR-let-7 and modifiedmiR-145 nucleic acids of the present disclosure when compared to thecontrol.

As yet another example, modified miR-200b (5-FU-miR-200b) and modifiedmiR-489 (CMM489) significantly increase the sub G1 and G1/S ratio ofbreast cancer cells in a population when compared to controls (i.e.,native exogenous microRNAs or vehicle alone, NC). See FIG. 16C and FIGS.20B and 20C. This shows that exemplary modified miR-200b and modifiedmiR-489 compositions can treat breast cancer by inhibiting cell cycleprogression.

The effects of the exemplary modified miR-15a compositions on colonyformation by colon cancer stem cells in Matrigel matrix were alsoexamined. As shown in FIG. 10, while many colonies were generated bycells transfected with control miRNAs (FIG. 10, Negative), very fewcolonies were generated by cells transfected with unmodified miR-15a(FIG. 10, miR-15a). In contrast, in the case of cells transfected withmodified miR-15a, no colonies were observed (FIG. 10, 5-FU-miR-15a).These results indicate that the exemplary modified miR-15a compositionsof the present disclosure are indeed more potent inhibitors oftumorigenesis and colorectal cancer progression.

Modified miR-15a inhibits cancer development and progression in vivo. Acolorectal cancer stem cell mouse xenograft model was established thatincluded colorectal cancer cells that have been either pre transfectedwith modified miR-15a or negative control miRNA. Eight weeks afterinjection, tumors were measured and harvested. A drastic reduction intumor size for tumors established from CSCs expressing modified miR-15amimic (>25×) (n=8), as shown in FIG. 11.

The data presented here supports the viability of a novel modificationin which halouracils (e.g., 5-FU) is incorporated into a miRNA nucleicacid sequence to enhance the chemotherapeutic function of the nativemicroRNA molecule with or without the use of other chemotherapeuticagents.

Modified microRNAs are able to inhibit cancer development in aconcentration dependent manner and without the aid of a deliveryvehicle. As shown in FIGS. 6 and 15A-15C, the exemplary modifiedmicroRNAs tested were able to inhibit, colorectal cancer, gastriccancer, breast cancer, and lung cancer cell proliferation in aconcentration dependent manner (i.e., at various concentrations 50 nM,25 nM, 12.5 nM, 6.25 nM, and 3.125 nM). Providing further evidence thatthe modified microRNAs of the present disclosure can be used as ananti-cancer therapeutic for the treatment of many cancers.

Furthermore, to test whether or not the modified microRNAs of thepresent disclosure can be delivered directly to cells and taken up bythe cancer cells without the use of transfer agents or vehicles (i.e.,oligofectamine), MDA-MB-231 triple negative breast cancer cells weretransfected with miR-NC (negative control), exogenous unmodifiedmiR-200b or miR-489, 5-FU-miR-200b or modified miR-489 by usingoligofectamine or without delivery vehicle. As shown in FIGS. 17A-17Band 20A, the effects of expression of the exemplary modified miRs testedon breast cancer cell proliferation were monitored by MTT assay for 6days upon transfection or incubation. In the presence of oligofectamine,native miR-200b and native miR-489 reduced the rate of cellproliferation of MDA-MB-231 cells in comparison to control microRNAs(miR-NC). While modified miR-200b (5-FU-miR-200b) and modified miR-489dramatically reduced the cell growth from day 3. See FIG. 17A and FIG.20A. Unexpectedly, modified miRs were able to block proliferation ofMDA-MB-231 cells without oligofectamine treatment (without deliveryvehicle) whereas control microRNAs and exogenous native microRNA (i.e.native miR-200b) had no effects on proliferation without oligofectamine,as shown in FIG. 17B and FIGS. 21A-21B.

Furthermore, with regard to the use of modified miR-200b to treat breastcancer, after administration of a modified miR-200b a reduction offibronectin (miR-200b target gene) expression and interaction with TSwas observed, when compared to both exogenous native miR-200b andnegative control, as shown in FIGS. 16A and 16B. The results confirmthat modified microRNAs such as modified miR-200b be delivered intocancer cells and inhibit cell proliferation by modulating target geneswith or without delivery agents.

Modified miR-489 treats triple negative breast cancer. FIG. 18A and FIG.18B show that native miR-489, when administered to breast cancer cellswithout 5-FU chemotherapy reduces cancer cell proliferation in a mannersimilar to that exhibited when cells are treated with 5-FU alone.Notably, as shown in FIG. 19A, treatment of triple negative breastcancer cells with miR-489 resulted in a reduction of MDC1 and SUZ12protein expression, through the binding of miR-489 to a portion of theMDC1 and SUZ12 3′ UTR region that is complementary to a portion of themiR-489 nucleic acid sequence (i.e., CUACAGU). As shown in FIG. 19B, afurther reduction of SUZ12 and MDC1 (miR-489 target genes) proteinexpression was observed, as was an interaction with TS, when compared toboth exogenous native miR-489 and negative control microRNA, indicatingthat the 5-halouracil modifications did not inhibit the ability ofmiR-489 to bind to the MDC1 and SUZ12 3′ UTR region in cells and inhibitprotein production. This functionality ultimately led to a reduction inbreast cancer cell proliferation and development as shown in FIGS. 20Aand 22.

Modified miR-489 inhibits breast cancer development and progression invivo. A triple negative breast cancer xenograft mouse model wasdeveloped by tail vein injection of MDA-MB-231 breast cancer cells andtumors were developed over time. Mice were then injected with modifiedmiR-489 composition having the nucleotide sequence set forth in SEQ IDNO: 32, exogenous native miR-489, or negative control miRNA byintravenous injection with treatment frequency of one injection everyother day for 17 days and mice were euthanized and tumors size wasmeasured using imaging techniques. A drastic reduction in tumor size forbreast cancer xenografts was shown after treatment with a modifiedmiR-489 nucleic acid composition when compared to mice treated withnegative control microRNAs and mice treated with an exogenous nativemiR-489, as shown in FIG. 22.

1. A modified microRNA nucleic acid composition comprising a nucleotidesequence having at least one uracil nucleic acid, wherein one or more ofsaid at least one uracil nucleic acids is a 5-fluorouracil, and whereinthe modified microRNA nucleic acid composition binds to a portion of aMDC1 3′UTR nucleotide sequence set forth in SEQ ID NO: 33 or a portionof a SUZ12 3′ UTR nucleotide sequence set forth in SEQ ID NO 34
 2. Thecomposition of claim 1, wherein at least two of the uracil nucleic acidsin the nucleotide sequence are 5-fluorouracils.
 3. The composition ofclaim 2, wherein at least three of the uracil nucleic acids in thenucleotide sequence are 5-fluorouracils.
 4. The composition of claim 3,wherein all of uracil nucleic acids in the nucleotide sequence are5-fluorouracils.
 5. The composition of claim 1, wherein said modifiedmicroRNA nucleotide sequence comprises a microRNA nucleotide sequence ofmiR-489 as set forth in SEQ ID NO:
 31. 6. The composition of claim 5,wherein said modified microRNA nucleotide sequence isCGACGGCAU^(F)AU^(F)ACACU^(F)ACAGU^(F)G [SEQ ID NO. 32].
 7. Thecomposition of claim 5, wherein the modified microRNA nucleic acidcomposition binds to a portion of the MDC1 3′UTR nucleotide sequence setforth in SEQ ID NO:
 33. 8. The composition of claim 5, wherein themodified microRNA nucleic acid composition binds to a portion of theSUZ12 3′ UTR nucleotide sequence set forth in SEQ ID NO:
 34. 9. Apharmaceutical composition comprising at least one modified microRNAnucleic acid composition of claim
 1. 10. The pharmaceutical compositionof claim 10, wherein said modified microRNA composition comprises anucleotide sequence of CGACGGCAU^(F)AU^(F)ACACU^(F)ACAGU^(F)G [SEQ IDNO. 32]. 11.-21. (canceled)